From experience playing 4e when it first came out, I'd have to agree with the assessment that a math fix is/was more useful in a "2008 product only" game. Some of it could have been our DM, but monster defences were way too high, or our bonuses too low, and the monsters had far too many HP.
I should qualify that. In order to adequately challenge the party, especially in terms of monster damage output and longevity, encounter levels end up being in the Level +2, +3, or even +5 range, but the problem there is that the defences far outstrip what the PCs can hit, so you end up with long, grindy, At-will whiff-fest combats that can even be really swingy if the PCs roll really bad, and/or the monsters roll really well. Sometimes, it was not much fun at all, and frustrating nearly all the time.
For a good example, even the designers were aware of the kind of fight needed to challenge a group; the introductory module in the Forgotten Realms book features a Level +5 encounter. Doing that in a post MM3 game, would be a surefire way to get a TPK. At-level combats are challenging, while level +2s are downright dangerous. A Level -1 encounter is sufficiently tough for routine or minor fights now. Solos are also much improved, many of which are even usable without minion backup now.
