[spyu]

I see this question a lot and have also heard it being discussed on the flip side during live play(How a certain live player would do online). I don't have a whole lot of online experience, but I would say that the differences are significant and your ability to succeed in one medium vs the other really depends on the individual. Some can't beat either, some can beat both, and some can beat one but not the other at certain limits.
Also I don't believe the limits you play necessarily determine how hard or easy a certain game is.
I think you won't find that much difference in the locals/tourist ratio between 1/2 and 2/5. Depending on where you play they will play almost the same way. Just depends on the table you're at. Sometimes the game is super tight, sometimes You open raise for 30 someone reraises to 75 and the whole table calls behind. I don't know if in online games, there are specifics corrolated to limits with all these number categories that you quoted. But in live play you just have to sit down and see what the table is like because it varies so greatly.