Or how do they generally play currently? I'm talking NLHE 2$, 5$, 10$.

I played a lot a few years ago and am thinking of starting again, but I keep reading how they've changed. No one really goes into depth, though.

So what is it? Just a higher number of sharks using tracking software? Fewer people overplay high pocket pairs? People play draws more aggressively? Harder to make money on set vs overpair? etc?

OK, first I should say that I don't play uNL, so take my hearsay witterings for what they are worth ...

There are fewer clueless fish playing uNL. Those guys definitely still exist that will play ATC and call any raise with bottom pair, but they are not around in the numbers that they were.

Tracking software is more widespread, but I don't think this is a major thing at uNL.

Many more people have read poker books, sites like this one, watched free youtube strategy videos etc. So there are more players that have some kind of clue about strategy, even if they don't execute it well.

There has been a large influx of grinders at uNL from countries with lower cost of living, and these guys nit it up while massively multi-tabling. They are hard to win stacks from, and the games have become nittier.

They're still really easy if you played higher stakes, if you were playing say 25nl 4 years ago then start at 2nl and just make sure you're winning at each stake then move up.

How would you generally go about exploiting players like this? Playing more aggressively against them and them alone, and hope they don't have an 'against hero' stat line on their HUD?

Or should I just nit it up myself? I won't be playing a huge number of tables, at first anyway.

Exploit them by folding when they want to play a hand.

Basically, it seems that for every n years that've passed, every stake is the equivalent of n stakes higher. So 10NL now is like 50NL in late 2011/early 2012.

They're still very beatable. Just not as they used to be.

The unl player in general has more knowledge of the game since there is so much info available on the internet, books etc. Here and there you'll find a 'pretty' solid 10nl player, but in general the best you will encounter is fairly decent. 99% in the micro's have a lot of leaks, which makes them still very beatable.

With a HUD it shouldn't be too hard to filter the nits out of the mass, and exploit the rest (even while multi tabling).

I agree with this. Pre-Black Friday I was a winning 50NL player, but I made most of my $$ through rakeback and bonuses. I recently came back trying to build a roll via .02/.04 NL, and it's more difficult than 50NL 5 years ago. I'm still winning over a decent sample size, but I'm trying to improve, because playing on auto-pilot like I used to do probably isn't going to cut it any any stakes above what I'm currently playing.