For what it's worth, I first starting BTC lending with BTCJam and in the last month or two have transitioned slowly toward BLC.
For whatever reason, BTCJam has gone noticeably downhill in the last several weeks. People seem to be defaulting left and right, so what few 'good' loans are left get snatched up almost immediately. I don't know what changed, but I can definitely say that BLC is a better platform as it stands now for the following reasons:
1) Quality of loans
There's quite simply fewer defaults, at least in my personal experience.
2) Shorter terms
Most loans at BLC are about 30 days, whereas more and more loans on BTCJ are 365 days, and I just don't want to go that far out, especially with the volatility of the cryptocurrency market.
3) The rates
I think this also relates to their superior rating system. I feel as though the suggested (but not mandatory) rates are more closely related to the amount of risk you're taking with any given loan. Plus, the fact that you can offer whatever rate you'd like to a buyer is a big plus since you can adjust up or down depending on what you think is fair, and the buyer can either accept your offer or wait for a better one to come along (at least to my understanding).
4) The social identity verification
I can do my due diligence by perusing someone's Facebook page, for example - a few of which look obviously fake and set off red flags, so I stay away. This simply isn't possible at BTCJ, which makes it a less desirable lending platform.
I will say though that, if someone prefers loans that are tied to the value of USD instead of strictly BTC, regardless of how the value fluctuates throughout the loan, there are generally more of those loans at BTCJ. Although USD loans do exist at BLC, they just aren't very common. I'm okay with this, especially since the loans are better all around, but it's something to consider if you're looking for that kind of security. Again though, since most loans are 30 days, I really doubt this is going to be much of a factor.
Loan notes might be a feature to consider adding to BLC. Sometimes people get freaked out about someone being late, and I like being able to buy them out at an even larger profit (or a larger loss if it doesn't work out).
Oh! I might also add that there's been an influx of crap loans at BLC that mostly seem to be originating from Venezuala and sometimes other South American countries. Apparently, they're getting fake documents to create these accounts, but the pattern I'm seeing so far goes something like this:
1) Rep loan, 7-day term, something small like .01BTC
2) Second loan, usually 7-14-day term, something slightly bigger like .5BTC
3) Third loan, 14-30-day term, usually 1-1.5BTC and usually defaulting
I've been burnt 3 or 4 times by these guys, and have decided to just filter out all loans from Venezuala for this reason. There are some legitimate borrowers from that country, but it just takes too much time to sift through all the crap loans from there to be worth the effort. It'd be nice if BLC could look into how these loans are getting through so that you can potentially resolve the issue.
Also, I thought it was odd that one person commented about this exact thing in the comments of the loans that were suspect, and admins deleted the comment. Sure enough though, the loans defaulted. I don't think this is necessarily shady of the admins, but I don't see why the comment was deleted, especially when it has turned out to be a genuine issue.
Anyway, I can't speak to the efficacy of BTC Pop, as I've never used the platform, but I'll have to give it a go and see if it's any better or worse.
BTCjam has been messing with peoples account and not letting them pay as well . crappy service