The 750 is a slick little amp- Even with all the great debate over the power output, you can dial in just about anything you need.
I just sent mine back, but it's only because I need stupid output watts from time to time. For 90 percent of my gigs it would be the perfect head, but it's the ten percent where you don't have the volume that made me decide to send it back.
The presets, tuner and the footswitch make for a cool, flexible head that does have more headroom than the 238 watt power section implies. The compression is good, the flexibility to shelve or dial out mud and boom on one end, dial out the clank on the top and still have tweeter control on the extreme top end is really nice. You can get it to grind a little, or push a lot of clean bottom end.
I did have a few niggling issues- I had a preset "stick" and refuse to disengage on stage, (I missed the "mute" button and wasn't using the footswitch") and powering it down didn't help- I had to dial it in on the fly over two songs to get a useful tone again.
I ordered an SVT-4 which arrived this morning- Late. (It was supposed to have been here Friday morning...) The 1600 watts is hard to argue against- Sooo, I heave it out of the box, plug it in-No power light, the EQ section didn't work at all and it was putting out an incredibly feeble amount of volume in bridge mode. By feeble, I mean- State-of-the-fart tone and volume.
A big, expensive, bleeping anchor.

If the replacement doesn't A) Arrive on time, and B) in good working order, and C) Most important- Prove to be reliable, Ampeg and GC is going to wish they'd never heard of me. If Jimmy is the Ampeg Jesus, I'm going to be the Ampeg Ant-christ.
Now- With all that being said- I LIKED the 750. YMMV. For most gigging players, it's a great little head. I am equally willing to give the SVT a chance over the course of a few shows to see what it can really do. If I had that kind of money, I'd keep both.