We all know about 'dead levels' en route to level 20: Those levels with no feat selections where all you do is allocate skill points and go on.
But in epic levels, to have THREE of them all very close together, is torturous.
In heroic levels, at least the player has the choice of which class to advance in, and gets to allocate remaining skill points in whatever configuration they desire.
In epic levels at 22,23, and 25, you're just getting epic 'commoner' ranks, so you don't get to choose classes. You get one screen that lets you know how many HP you get. That's it. Hardly feels epic.
I know what you're saying. "But what about Epic Destinies?" These are a separate form of advancement from heroic character levels (commoner epic ranks are lacking in caster level advancement.) They spice things up at 26 and 28 with ED feats, but why the lack of effort at the beginning of Epic?
This brings us to the sad conclusion that there are NO single classes epic toons. You CAN'T be single classed. You get commoner levels. It's why spell DC doesn't go up after 20 without ED's.
This is terrible. I suggest you allow people to advance beyond 20 in their chosen class. If someone wants to be a 28 wizard, it should be possible. The whole ED system is interesting to a point, but the real interest is in true character development beyond 20.