To be honest, I bought my SRs from Aerohead a few years back. I havent bought any thing from them since. The heads I have seen (one pair of 452 B heads, one set of "915" LA heads) was ok in quality. The work was not top notch, the parts were lowest grade possible for that application. About what I would expect for $500/pr tho. There are all kinds of shops out there. Some have the best equipment, some have good machinists and care, some have a dollar driven business, some will do the least they can for you to feel your satisfied. The shop I use (and I do roughly 10-12 engines a year thru them, plus misc onesy twosy heads/blocks) has top quality machines, and the guys that use them are 30+ year veterans doing only automotive, both are racers in their own rights, and the thought is "we can do it" no matter what the application. I have yet to get out of the shop with a set of heads built from my supplied castings for under $800. But, I also have yet to have any problem with any of the work they've done. You get what you pay for. If a shop makes money buy volume, the work and parts are cheap. If they make it off quality, the work and parts arent cheap.
Would I use Aerohead, if I need to buy brand new stuff, yes. I wouldnt pay for them to do any work for me. Besides, with shipping, your local shop may be doing a better job, and if they have an issue, you can drive it over to them. Think about it this way. They are selling you the cores, and buying oversize valves and springs. How much can they really spend on quality help to correctly set these things up, and still make money on them?