So. 4e is proud of its math (and, conceptually, I agree that the flat advancement is an improvement). But what happens in practice?
From the DMG, it is clear that NPC attack/defenses are supposed to scale as 1*level. How about PC attack/defenses? They get:
0.5*level (base scaling)+0.2*level (+1 enhancement/5 levels) + 0.15*level (3 stat points in primary stats/10 levels)=0.85.
Armor scales better:
light armor scales the best (+2 masterwork/30 levels=+0.067) for 0.917 while heavy armor gives
0.5+0.2+0.2 (masterwork, not stat)=0.9*level.
Masterwork armor is problematic though in how uneven the bonuses are: you get a full *+4* to AC going from +3 heavy to +4 heavy (and, with the scaling, it will take you from sucking to on par). Further, in the above I assumed you get a primary stat to every defense. Clearly, you don't. Feats can help (1 AC point from an armor spec, 2 defense points from the paragon defense feats), but non-primary stat defenses are hopeless and the armor spec feats have brutal requirements.
0.85 =/= 1. Is this important? Well, by level 13/14 the party is 2 points worse compared to same level NPCs than they were at lvl 2 or so. By lvl 28 it's 4 full points. Even 2 points is big on a d20, and 4 points is huge. This applies to both offense and defense too. So if at levels 2-3 the party is facing off against lvl+2 foes, at lvl 13-14 they should be facing off against lvl foes and by lvl 28 they should be facing off against lvl 26 foes. In the recent podcast, PCs in the mid-teens are facing off against +3ish foes and having a very hard time hitting: +3 for level difference + 2 for differential scaling=NPCs have +5 to hit and AC. No wonder the podcast fight was boring.
In sum: 4e math, despite being supposedly fixed, still breaks over large level ranges. The theoretical level range of 4e is easily large enough for 4e's math to break. In the paragon tier, the increased number of per-encounter/dailies may make up for worse to-hits/defenses, but by the epic tier you have a choice of facing off against lower-level foes or whiffing continuously and falling into at-will grind-fests. As if the padded-sumo effect wasn't bad enough.
From the DMG, it is clear that NPC attack/defenses are supposed to scale as 1*level. How about PC attack/defenses? They get:
0.5*level (base scaling)+0.2*level (+1 enhancement/5 levels) + 0.15*level (3 stat points in primary stats/10 levels)=0.85.
Armor scales better:
light armor scales the best (+2 masterwork/30 levels=+0.067) for 0.917 while heavy armor gives
0.5+0.2+0.2 (masterwork, not stat)=0.9*level.
Masterwork armor is problematic though in how uneven the bonuses are: you get a full *+4* to AC going from +3 heavy to +4 heavy (and, with the scaling, it will take you from sucking to on par). Further, in the above I assumed you get a primary stat to every defense. Clearly, you don't. Feats can help (1 AC point from an armor spec, 2 defense points from the paragon defense feats), but non-primary stat defenses are hopeless and the armor spec feats have brutal requirements.
0.85 =/= 1. Is this important? Well, by level 13/14 the party is 2 points worse compared to same level NPCs than they were at lvl 2 or so. By lvl 28 it's 4 full points. Even 2 points is big on a d20, and 4 points is huge. This applies to both offense and defense too. So if at levels 2-3 the party is facing off against lvl+2 foes, at lvl 13-14 they should be facing off against lvl foes and by lvl 28 they should be facing off against lvl 26 foes. In the recent podcast, PCs in the mid-teens are facing off against +3ish foes and having a very hard time hitting: +3 for level difference + 2 for differential scaling=NPCs have +5 to hit and AC. No wonder the podcast fight was boring.
In sum: 4e math, despite being supposedly fixed, still breaks over large level ranges. The theoretical level range of 4e is easily large enough for 4e's math to break. In the paragon tier, the increased number of per-encounter/dailies may make up for worse to-hits/defenses, but by the epic tier you have a choice of facing off against lower-level foes or whiffing continuously and falling into at-will grind-fests. As if the padded-sumo effect wasn't bad enough.