My #1 piece of advice for epic games: Rework epic spellcasting or have everyone play a full caster.
The power gap for spellcasters actually widens in epic, and it grows with every level, even when you don't try to cheese the creation DC rules.
Agree 100%m Meleers can still do a shit ton of damage, but when a spellcaster can autokill every enemy, its just not fun for the fighter or the DM.
I have the exactly opposite experience: Since most enemies are immune to every non-damage effect, your best bet will be to hit them in melee or blast them with spells that do at least 2d6/CL. Those should of course be Quickened, Twinned and Intensified. If you play it right you can one-round most enemies with those kinds of effects.
Epic Spells do of course do shift balance even more towards casters. However, in this case cheesing the DC costs is usually a way to level the playing field, because in that case a caster might be willing to get an epic strength buff to buff the BSF.
And EjoThims is right: Non-casters will feel VERY underwhelming in Epic. Even Initiators, since there are no epic progressions, and any maneuver that doesn't include a full-attack or pounce is basically useless. There is one exception to this rule: Supercheesed chargers, like the Hood builds, still perform pretty well, IF they can find a way to cast Wraithstrike.
Also, I recommend computerising everything, especially attack and damage rolls, AND not worrying too much about minute details. Who cares if there is a D6 more or less? In my epic game if I were to field everything at my disposal I would be able to do about 35-40 attack rolls AND cast three spells per round. Without computerising everything and NOT worrying about a few minor details that would just take forever.