Having gigged a SWR 750 head through a hartke 410 and ampeg 810 for about 17 years, I can honestly say I no longer like SWR amps.
It was reliable. But I disliked it more with each passing year. If I had had the money, I would have replaced it sooner. Based on whats available today, I wouldn't touch SWR anymore. I eventually replaced it when it started making weird intermittent static noise.
It sounded good, sure, thats why I bought it. The tone was as everyone says, clear and scooped-ish. It was great for active basses, but passive basses sounded plain through it so I used a VT bass pedal with my passives. One thing no one mentions, maybe its me, but at higher volumes, the low end, while sounding great, was always the dominant sound of this amp, and other SWR amps I've used. Like it couldnt articulate mids and highs passed a certain point. Sometimes I feel like it was the best amp for reggae tones, but playing in a rock band was just not the right setting. I did find that high end disappeared when played through my ampeg 810, I'm guessing the amp was designed to work with tweeters, of which the ampeg has none.
I never understood the aural enhancer control. In the years I owned it, i never moved it from the 1o'clock position, it just didn't sound good in any other setting. Pointless.
When the preamp clipped, it sounded like crap, and I could never get the gain passed 12o'clock. The limiter circuit was very sensitive causing pumping and drained tone quality, so I almost always had it disengaged. This head also had one of the worst sounding effects loops I've encountered, so I never used it.
The power switch was weird sometimes, but that could have just been mine.
It came with a proprietary footswitch with a five pin connector. It should have been a trs cable or unbalanced connector. I damaged one of the pins and was never able to use the footswitch again.
My biggest pet peeve of this amp: I always felt it was way underpowered. I mean, it could get real loud but for an amp that said 750 watts right on the front, it was a wuss. It pretty much stopped outputting volume after the master reached the 12o'clock position, right when I needed it to, even at 4ohms.
My Quilter BB800 smokes it in the volume department, and only weighs 3 pounds. That is no understatement, I could hardly believe it when I played it through my 810 for the first time.
Nothing wrong with SWR, there are just better choices now.