I think part of it would depend on what kind of widget you're selling. I don't see too many "product" offers with the newer networks that offer all the zip submits and clubs and whatnot...and the ones I do see have pretty high commissions (compared to typical e-commerce stores), so I would think you'd need to have a similar program to do well with those networks.
I work with ShareaSale at my day job, and we've had a program there for about two years. Twice now, I've taken the time to call CJ and Linkshare to discuss switching, but they've never really offered anything we weren't getting with SaS for a lot less money. CJ did mention some add-on services they can provide, but there are a lot of extra fees for those services.
I think the biggest thing that turned us off to CJ, though, was the $500 monthly transaction minimums fee. At SaS, it's just $25. I'm sure that CJ has more affiliates, but it seems like all the serious "consumer product" affiliates I've met have accounts with all the major networks anyway, so I really doubt we're missing out on a ton of great people because of the network we're using. We also determined that we'd need to drop our affiliates' commissions if we switched networks, since their fees would have been higher - and that would just suck.
Personally, I'd skip CJ and Linkshare and use the leftover money to promote your program by going to shows, running forum ads about your program, offering bonuses to affiliates, and/or giving a better commission rate.
