sony lens help, prime or zoom?

[lexie]

i'm looking to add to replace my 18-55mm kit lens but i'm struggling to decide between the sony 35mm f1.8 and the tamron 17-50mm f2.8 non-vc.

i know the obvious advantages/disadvantages of both lenses so i'm looking for info on each lens from people who have used them. mainly the following points:

the sony seems to be pretty flimsy looking but it's cheap as chips at about £150. is the build quality as bad as it appears? my all-plastic kit lens feels like a toy compared to the 70-210 'beercan', but maybe that's an unfair comparison.

would the sony 30mm f2.8 be any good for a walk about lens or is it specifically a macro lens? also cheap at £150

then there is the tamron. i've heard good things about this lens, better iq than the kit lens with the benefit of constant 2.8. with the sony steady shot i'd get the benefit of stability without the loss of quality the vc version brings with it according to a lot of reviews.
is the iq good enough to compete with that of a prime lens? is distortion an issue at extremes?
the physical size compared to the primes isn't an issue.

my current lens line-up is :
sony 18-55mm kit lens
minolta 50mm f/1.7
minolta 70-210mm f4 'beercan'

in an ideal world i would get both, but i'm planning to upgrade my body in the next year or so aswell (whenever sony get their act together and release the a700 replacement)
if the 30mm f/2.8 macro can be used as a viable alternative to the 35mm f/1.8 i could be tempted to buy both as it would cover an extra base.

 

[gerrard8]

I have the tamron 17-50 on my 580 but sadly not had much of a chance to get out and about with it yet but the few shots i have taken in the garden and around the house have so far convinced me i did the right thing in buying it.

I have the sony 50mm 1.8 and it is plastic but i use it for photographing breakwaters,groynes and ground level shots of the incoming tide and i really like it.
Not sure about the 18-55 sam but it has some good reviews and is supposedly better than the old 18-70 but as yet i've not given it a try as the tamron is its replacement.

 

[lexie]

thanks for the input frank, good to hear you're happy with it. i know the 18-55 gets better reviews than the 18-70 but after using the other lenses i have for a few weeks i'd like to have a 'standard' zoom which can offer the iq to keep up with them. failing that a wider prime than the 50mm i have will have to do.