I like both equally. I own and used a SVT-CL as my primary gigging amp for a number of years. Eventually, I put an 810e under it. With all that weight, it became my outdoor-gig-only rig. It does the LOUD thing like nothing else I've ever owned. After a point, it quits sounding louder, per se, but starts sounding fuller. And it sounds really good at any volume.
I also own and used an SWR Super Redhead for a number of years. I put a Goliath Jr under it, so I ran it with four 10s. I understand the "hifi" stereotype, but it will give a good "vintage" tone too. Nobody likes to touch their amp EQ anymore, and SWR's magic lies in the eq section. It sounds great, too, but it doesn't get nearly as loud as my ampeg. Of course, its not pushing the wattage like some of the bigger SWR heads.
Here's the thing. If I run my CL through cabs with horns, I can get a fat vintage tone, a hifi tone, or any other tone I want. If I turn the horns off on my redhead, I can do old-school vintage, or I can dial the horns up and cut your head off with top end.
The ampeg gets louder. The ampeg has a bigger bottom end, so it is easier to dial in thicker tones. The SWR is quieter, but has a more verstile EQ section. It has plenty of low end, but not a ridiculous amount like my ampeg. The SWR always has enough presence to come to the front of the mix, but can be subtle enough to sit in the back.
Both are winners. If I had to pick one amp, I'd keep my redhead over my svt-cl.
I am currently using a LMII and two PS112s as my main rig, though. Only rig that fits in my new car.