I hate to be the desenting opinion here, but Carvin's are great guitars. I am on my third--one custom built and two eBay finds. They offer things that Warmoth simply doesn't. If you are looking for a neck-through or a set neck, you can't get that here. As for whether Carvin or Warmoth has better build quality, that is probably a debatable point, but Carvin's are very well built. Admittedly, Carvin is VERY limited on their bolt-neck options, which is where Warmoth plays, so both can coexist very nicely.
As for the original question of Carvin pickups, I happen to love the C22B bridge pickup. I had one in my DC127 and in my current CT3T--both mahogany bodies--and they give me a great straight-ahead rock tone. Harmonics are nice. I have a Dimarzio Tone Zone that came in a Wolfgang that I own and I am thinking about replacing it with another C22B. The TZ just doesn't do it for me. For the neck, I really loved the H22N that I ordered in my DC. It is a very articulate pickup that does great legato leads and such. I have the C22J in my CT, which is nice but not as good as the H22N. I had the M22SD in my 1989 DC127 that I refinished. That pickup in that guitar (all maple) was too harsh for my tastes.
If you choose to go with a Carvin, don't discount the pickups right off the bat. A lot of people like them and stick with them. Give them a listen for a month or so and see what you think. If you really decide that you don't like them, there are a lot of options out there. The fact of the matter is that Carvin is a SEMI-custom shop. They don't do full custom guitars. How many guitar companies offer you your pick of any pickup from any manufacturer? I am not familiar with many. I think that Jackson Custom probably does. Probably a couple of others. Generally, if you want your own unique pickups on a guitar, that is something you can pick up after the fact. With Carvin, you at least get to customize a guitar to your liking from a huge list of available options, and the prices are generally better than most full-on custom shops are going to be able to get you.