Well, I had a quick look at both your insect and flower images(very nice they were too) and would agree, its tough to say what camera took what shot?? I didnt look at the exif data of each image either(because that would spoil the fun!) but im inclined to think that the FZ200, would produce the better quality images?
Putting aside the SX240 point and shoot, which I only used for the flowers and can't use an achromat, I was using the same achromats (Canon 500D, Raynox 150 and Raynox 250) with all four of the cameras - three bridge cameras (Canon S3is, Canon SX10is, and Panasonic FZ200) and one micro-four thirds camera (Panasonic G3). On the face of it, I would have expected the FZ200 to produce better image quality than the SX10is or S3is, because it is more modern. I would have expected the G3 to produce better images than any of the bridge camera because it has a sensor 9 times the area of their sensors. But it didn't work out like that.
Part of the reason for the G3 not being (for my purposes) noticeably better than the bridge cameras has to do with my liking deep dof and preferring to use natural llight. (I do use flash quite a lot these days, but I still prefer to use natural light.)
I like as much dof as I can get for my close-ups of invertebrates, and I typically use the smallest available aperture I can, which is f/8 on the bridge cameras and f/22 on the G3. f/8 on a bridge camera produces about the same dof (and about the same loss in detail from diffraction) as f/22 on the G3 (or for that matter an APS-C camera like yours).
Using a small aperture, and using natural light, often leads to slow shutter speeds. For example, suppose I get a shutter speed of 1/20 sec when using f/8 with ISO 100 on the FZ200. I don't really want to be using a slower shutter speed, so if I take the same shot using the G3, and want to get the same dof, I would have to use ISO 800 (with 1/20 sec and f/22). And in fact, ISO 800 turned out to be my baseline ISO much of the time with the G3 because I am often in the realm of pretty slow shutter speeds. And in terms of IQ, ISO 800 on the G3 is fairly similar to ISO 100 on the FZ200 or SX10.
So, in practical terms, a lot of the time I didn't gain much from using the G3. And once I got the FZ200 I realised that I found it much easier to use than the G3. I find the G3 quite fiddly to use, and it doesn't have much by way of user-definable functions for buttons. In contrast I find the FZ200 is much more straightforward to use, with the controls I need readily to hand without needing to dive into menus. This is partly because it has much better provision for user-definable buttons than the G3.
The FZ200 turns out to have some other advantages (for me). You can sync the flash at any shutter speed, which is great for fill flash on bright days. The G3 only syncs up to 1/160 sec, and beyond that you have to get into FP/HSS flash, which I find a pain to use. I mount the achromats on a tube which provides some protection for the camera lens out in the field against dust, pollen and dew. It also means that I can zoom in and out between different framing/magnification for a particular scene (which I do a lot) without moving the camera. Physically, the FZ200 sits more firmly on the focus rail compared to the G3, which has to be mounted on a little platform to give the lens sufficient clearance above the focus rail, and the little platform and hence the G3 tend to rotate.
There is more as between the G3 and the FZ200, but that will do for now! You get the idea.
I suspect there is another reason why the cameras appeared to produce rather similar results; the post processing I use and the fact that I rarely do big crops and I limit the size of the processed images to 1100 pixels high for screen viewing. I reprocessed all the originals of those images (mainly JPEGs btw) at the same time, fairly recently, using my current post processing techniques. It turns out that images from all the cameras contained enough information to produce half-decent images at the limited size I produce, even the 6 megapixel S3is.
I had the FZ28, before i got the FZ45, in some ways my old FZ28 could out perform the newer FZ45! My mistake, was that i should have gone for the FZ35/38, because that had the 12 megapixal sensor, where as the FZ45, got caught up in the "more mega pixels is better" game/race.
My FZ45 has the 14 megapixel sensor, which makes it a poor performer in dull light. In fact, once you shoot at ISO's beyond 250/300, the image quality is very poor! Hence the reason i use the camera in Macro Mode sub-setting "Objects", because in this mode, you can shoot at ISO 80! with good light. Although at ISO 80, you will have problems with too much light, so its finding a good balance, and shooting plenty of images, of chosen subjects.
If i can set up the FZ200, to capture images, as my FZ45 can(with the help of a Raynox macro lens!) then im considering getting an FZ200 sometime in the future. Since Panasonic dropped the megapixels back down for the FZ200 sensor, I was under the impression that it was capable of producing better quality images, in low light situations...an area that my FZ45 fails in.
You need to be cautious about that. The FZ200 has a reputation for being particularly noisy. Is there any chance you could borrow an FZ200 for an hour or two? Or I could provide you with some higher ISO (JPEG and/or RAW) examples if you like. I always shoot RAW with the FZ200, which avoids the detail-squashing effect of JPEG noise reduction on the noisy images. I have noise reduction for the RAW files fairly well sorted so I can get the combination of noise control and detail retention that suits me. This quite often includes using two layers in CS2 (after the main processing is done in Lightroom) to selectively denoise backgrounds. So, given the way you work, as described in your
Macro/Close up, of Snake, Lizard, Butterfly thread, the FZ200 might not be the right tool for you.
One thing you might want to do is to hang around the Panasonic Compact Camera Talk forum at dpreview, see what is being done with the FZ200, and see what settings people are using for shooting JPEG. there has been a lot of discussion about that over there, and it is a very friendly and helpful forum (unlike some of the other forums on that site). Some Flickr FZ200 groups might be of some use too.
Just to throw a spanner in the works, i have also owned a Nikon D5100, and i now have a nikon D7000...i also recently bought myself a 105mm macro lens for the D7000, so im hoping this combination will allow me to capture better quality macro's, than my humble FZ45!!!
You might do better to use the D7000 and the 105 than consider a new bridge camera to use with the Raynox. At least give it a good go for a few months before thinking about another bridge?