Pete, I've looked at both sets of images on my laptop (crap screen).
The first set are very soft, and the reprocessed set seem to have a dark halo round the subjects.
They're going to be cutting them out so that wouldn't matter.
I think the main problem here may be down to your technique on the shoot.
I myself would have used a smaller aperture say f8-f11 under the studio lighting.
This would have probably negated the out of focus look the images have.
Definitley something to remember next time. I guess I was thinking "People, f/2.8"
Personally I wouldn't offer any sort of discount, but would offer to reshoot foc.
Hire a lens if you need to, and use this experience as a learning process.
HTH
Already offered and they didn't think it was feasable. As for renting a lens, it would cost the price of the lens in a deposit. They got back to me today asking for 45 shots. Seems a bit odd if they were that unhappy.
I think they are entitled to expect the images to stand up at 1/1 size, anything else is relying on reducing the shot. Time to start working your images at 100% perhaps.
No hug from me either but I think you've more than earned a
Ta I will be checking my images at 100% and I will be buying only L glass from now on. While Sigma is great for a hobby lens, I just can't afford to trust it for professional use. I need to know that my equipment will perform. Whether I will is another matter