Well, with 3.5 I started installing hacks and got into how the template system works and so on. Still After looking over the list of hacks actually installed and active on my board it's ok in my opinion. Most of them are under the hood things. With a few exceptions like vBShout (currently disabled tho) or vBIbProArcade (after all this is a game related board). One thing to keep in mind tho, even with a lot more hacks installed you can keep your board neat and tidy looking, but that involves lot of template redoing and includes much fun in the next update.
But hey, playing around with vB can be fun, or why else are there so many Coders around

?