I have played in and run quite a lot of different superhero games over the years, and my experience has been that they nearly all have good points and bad points. D6 powers is one of the games that has many more good points than bad in my view.
As you might expect it is firmly based on the skeleton of WEG's D6 system as used in the orginal Star Wars rpg, but also takes inspiration from WEG's DC Universe rpg. However, whilst DCU uses a variant of the D6 system (called D6 Legend if I recall) using special 6-sided dice with symbols, D6 Powers uses standard D6.
What's to like? A good reliable system that is quite intuitive in many respects. A comprehensive power list that is not too complex to deal with (sorry, Champions but I'm looking at you). Masses of other D6 material (most of it now freely available) to raid for new stuff, NPCs, ideas etc.
On the down side. Combat could be a bit more streamlined, along the lines of Minisix. Large numbers of dice to add can slow things down a tad for higher level characters - there is an option for limitign the number of dice rolled, but I think I would have preferred that as the standard rule. The Strength chart for lifting is also a bit odd as the difficulty numbers reach various break points at 6D, 11D, 16D, and 25D - so the difficulty to lift a given weight changes drastically when you pass a break point. I guess it stops super-strong characters rolling to lift things well within their capacity, but I find it a little odd.
Overall, highly felxible an dfun to play