Hrm. I dislike that those overlap with the to-hit bonus at even levels (2 4).
What's great about Masterwork armor?
Masterwork armor is required or AC for heavy armor users falls behind quickly. Godplate gets half of it's +12 over plate from magic, half from masterwork. It's only a 2 drop for light armor by high Epic, but it's suicide for heavy armor.
Actually, the bonuses from inherent to hit are not so poorly placed if you consider how poor the original to hit system was. Using inherent with a bonus at 5/15/25 (original Expertise rules) results in:
1st level:
2nd level: +1 from level, +1 inherent = +2 to hit
3rd level: 0 = +2 to hit
4th level: +1 from level = +3 to hit
5th level: +1 old style expertise (i.e. +1 at 5/15/25) = +4 to hit
6th level: +1 from level = +5 to hit
7th level: +1 inherent = +6 to hit
8th level: +1 from level, +1 from ability score = +8 to hit
9th level: 0 = +8 to hit
10th level: +1 from level = +9 to hit
11th level: 0 = +9 to hit
12th level: +1 from level, +1 inherent = +11 to hit
13th level: 0 = +11 to hit
14th level: +1 from level, +1 from ability score = +13 to hit
15th level: +1 old style expertise = +14 to hit
16th level: +1 from level = +15 to hit
17th level: +1 inherent = +16 to hit
18th level: +1 from level = +17 to hit
19th level: 0 = +17 to hit
20th level: +1 from level = +18 to hit
21th level: +1 from ability score = +19 to hit (note: epic destiny could boost this by one)
22nd level: +1 from level, +1 inherent = +21 to hit
23rd level: 0 = +21 to hit
24th level: +1 from level = +22 to hit
25th level: +1 old style expertise = +23 to hit
26th level: +1 from level = +24 to hit
27th level: +1 inherent = +25 to hit
28th level: +1 from level, +1 from ability score = +27 to hit
29th level: 0 = +27 to hit
30th level: +1 from level = +28 to hit
The PCs have a +1 advantage at levels 2 and 8, but are at -1 disadvantage at levels 11, 13, and at 19+. But by Paragon, PCs have so many options that it doesn't matter that much.
In the big scheme of things, +1 to hit for a level or -1 to hit for a level means that the PCs get an extra hit or miss once per 4- rounds. Yeah, that adds up a little, but it's pretty small in the big scheme of things.