I have a giant folder of GURPS 4e books I got from somewhere. I've been going through and trying to buy the real deal of any book that I find myself using regularly (which is a frighteningly large amount. My players are welcome and encouraged to use ANY book, in part because using other books means they actually are reading the rules and putting thought into their character).
I have the first two GURPS power ups, but have never taken a look at them until just recently, thinking they were Superhero genre stuff, which isn't of much interest to me.
I was mistaken.
Power Ups I; Imbuements is nice, gives options for people that can supercharge whatever weapon they use, where the ridiculous power is in the user, not the weapon. Good for high fantasy and whatnot. Didn't read through the whole one
But Power Ups II; Perks? Reading through it, I feel like I'd be tempted to spend 1/4 to 1/2 of a character's points on perks.Some of them offer significant benefits for the cost, and others just round out a character nicely.
There are apparently a TON of GURPS: Power Ups books, and they're pretty cheap for each. They will probably be consulted any time I'm building a character now if I'm not barred from using them. If you haven't taken a look at them, reconsider.