The mechanical aspects are bad enough. They are all too large.

Don't be so sure these days. I've managed to buy golf ball bulbs only
slightly larger than incandescent ones. They are half the size of an
incandescent GLS.

My main issue is with the appalling quality of the light produced.

Many bulbs are fine these days. The main problem is that it is a bit hit and
miss when you buy a bulb. Some are excellent. Some are dire. Some sort of
labelling about light quality could seriously help here. Perhaps as well as
the A-G scale for energy efficiency, they could institute an A-G scale for
spectrum quality.

Christian.