I found it easier than 1e (and to be honest, we were using a similar mechanic in 1e because as you say, the multiple 20s was just too clunky). In fact, I found it easier than ascending because all the modifiers were already calculated up front (like bonus to hit, etc.)
THAC0:
I rolled a 16, looking at my weapon entry (which had all bonuses already factored) on my character sheet, a 16 hits AC 2 or worse.
Ascending:
I rolled a 16, now add +2 for strength, +1 for the weapon, and a BAB of +1, so I hit AC 20 or worse.