It really did feel like the pack was centered around Mekanism but having played on 3.1 for some time now I think the changes made are for the better. There are a lot of new options for power generation that are really specific to what resources you have available. Like the culinary generator for instance. If you have a huge farm and you're not eating all your product you can use the excess to make some electricity.
The addition of chemistry is a lot of fun. I've had a great time exploring the chemical makeup of all sorts of things and synthesizing iron from netherrack is just plain neat.
Through the miracle of safari nets, a sprinkler system, and a steady supply of oxygen I have an enclosed farm with tons of flowers, sheep, and cows ON MY SPACE STATION.
I think if you just give it a chance the learning curve is not that bad and all of the major glitches that kept my last voltz server constantly down have been corrected.
New voltz has my vote!