Well, here's my 2cp.
First, there's a significant difference in the quality of HERO 4e and HERO 5e. I had 4e. I sold it on ebay, hoping someone could at least make a nice coaster out of it. I flipped through 5e at the FLGS and couldn't believe it was the same game. I am very happy with the purchase of 5e and hope to run a game of some sort if I ever get time.
Second, I've played a lot of GURPS and even though I haven't played HERO, I like the design of the rules better. In GURPS, you have the standard rules and then bolt-on rules for everything else (computers, magic, psionics, vehicles). In HERO, everything runs of the same core rules. A magic wand, a pistol, and a bow that all do the same damage all cost the same points.
Third, there is a big learning curve, but some of it is imagined. I've seen plenty of game systems for just about everything under the sun. I even managed to understand char gen in the newest edition of Mechwarrior. I had to read through the basics of the rules a few times before I got it. Once everything clicks though, it's pretty darn easy.
Next, don't get hung up on it being a "supers" game. With the right ground rules and point limits, HERO can handle just about anything you want to run. There's official and fan-created material for supers, low fantasy, high fantasy, swords and sorcery, cyberpunk, space opera, hard sci-fi, pulp adventure, and just about anything else you can think of.
Finally, as someone said on the HERO boards, "there are usually more ways to build a power in HERO than there are people who want to build it." That's an exaggeration, but not by much.