I think you'll find more "for" than "against". And for the statement: "Just look at this site how many have problems." That's just because people don't post about their slides unless they "do" have a problem. How many hundreds (maybe thousands) don't have a problem? We'll never know because it isn't posted.
As for me, I've had two rv's with slides and two without (only because they didn't have slides back then). I have two slides now, and yes I have had a problem with one, but once I found out how to adjust it, I haven't had any further problems. A little annual maintenance on the seals, awning, and tracks will go a long ways in preventing problems.
I'll go on record as saying I'll never have another rv without them...in fact, our next rv will have twice as many as we have now!
Ron