If this is directed at me - the character is 25th level and already has TWF and TWD - I'd have to retrain feats and replace items to get the other things suggested - it's really too late in the game to make these changes.
Ultimately it all relates back to the OP in that the greater damage our characters take the stronger the need for going nova has become and the fewer encounters we can take on before having to take an extended rest.
Before the MM3 changes - we got hit quite a bit, but we could ride out the damage better. Now - well the last time we played we had 2 characters repeatedly being taken to low teens and single digit HPs - a single concentrated attack when down that much could flat out kill a character.
I don´t want to tell you, that enemies aren´t much more challenging, when facing the same foes as before. Really, i don´t.
I even expect them to be quite deadly. I have not been that high. But from a theoretical point of view I expect monsters to be a better experience.
Problems before the math change:
1) Defenses of monsters at higher levels too high.
2) HP of monsters, especially elites too high.
3) Damage sometimes much too low, especially when facing prepared players.
4) Hit chance too high so that investing in defenses feels useless
5) 10 Encounters in one day = 1 day per level
6) To challenge the party, you need to use even higher level monsters. All the above except 3 worsens, but 3 does not improve significally...
The easiest solution (IMHO): raise damage! Use lower level monsters!
1+2) solved
3+4) solved by definition!
5) Solved
6) higher level monsters are now equal level foes that hit roughly 40% in an organized party before pumping up.
In my humble opinion a desired solution. Actually expertise in a way did the opposite: you thrash monsters, as you usually hit them -> you need to face higher level monsters -> those have higher HP.
Maybe the most simple solution for your DM might be banning expertise feats. And just use monsters of 3 levels lower. This should instantly make your combat experience better.
Expertise was a mistake, promoted by those people who believe offensive is the best defensive. Which would be true in a system where your goal is kill the enemy as fast as possible (A MMO). In a system where the DM tries to give you interesting challenges, thrashing all monsters in a single round is the most unfun possible.
Many of you forget that an RPG is a dynamic system, unlike a computer game.
Also going nova should not be your standard tactic. As you expend your resurces to save other resurces you unbalance the dynamic. In earlier editions, wizards always could go nova. They didn´t, because you don´t know what you face next and first try to "eliminate the most dangerous foe, by the cheapest way possible"
In 4e terms: use an appropriate encounter power. Dailies for most classes are not the standard procedure.
An assasin (executioner) is the prime example: it choses a key foe and takes him out in a single round. Maybe he first lets a different character chose it to make sure it goes down to 10 or less hp with his limited encounter nova, drawing an action point if needed. The important thing here is that he can´t do it with all enemies, but with a key one. (Maybe the soldier and flanking partner of the skirmishers, or the leader)
Lowered defenses and lowered hp makes such novas more reliable.
