It's just the issue I have with something like Tracklib is that even though it's a great idea, when it comes to Hip Hop it kind of defeats the purpose.
It's always been that you go and find your own samples from whatever sources. Back when everyone was going to record stores, they would keep their records hidden from other producers that were in the store. No one wanted to give away their secrets. It was a rule. Now you can sample from anywhere online, so when you look at something like YouTube, that's a major source of material right there. And yet, some videos have tons of comments with people saying "OMG I'M GONNA SAMPLE THIS SO MUCH". So that means all these beat makers are hitting up the same video to sample. It doesn't make sense.
I used to subscribe to a few channels on there that posted tons of obscure stuff and it was a big source for beat makers but I don't follow those channels anymore because I don't want to sample what everyone else is sampling.
So the same with Tracklib - it's a great source but not for me. Yes, there's the big plus that you don't have to worry about copyright, so it really boils down to what you're trying to accomplish. If you're looking to put your music out there and sell it, or work with some rappers, then by all means use Tracklib. But still remember to use those samples in a different way than everyone else. Don't just loop it. Do something with the sample.
And if you're just doing beats for fun, there's no point in using Tracklib.