What is the forums opinion of SVS subs?

I do not have either, but both seem to be well respected.

One may also want to consider if integrating them into a system is easy or not.

They’re largely different designs. Yes, on paper SVS will deliver more deep bass per $ and sound quite good doing it properly set up, which is now much easier with their Pro series that includes integration software. Rel prefers to run off the speaker-level output and doesn’t offer integration software but by nature is easier to integrate without it. Bottom line, I’d take two sealed SVS SB1000 Pro subs at $1150 over one Rel sub because there’s a significant benefit to having two subs versus one if it comes to that. Past $1150, well, it’s all about budget. Don’t think you can go wrong with Rel, but then you start getting into Rhythmic, JL Labs, etc. territory that muddies the waters. Then it becomes a decision if using a speaker-level input or line-level input with integration shortware is preferable. Me? I’d read reviews of the various options and go with the one that offers the most of what you’re looking for. I don’t think you can go wrong with any of the above brands, but I will reiterate though that using at least two good subs is much better than using on great one. FWIW.

I have a micro 3000 and a PB2000, I enjoy them both. I have heard the REL is more musical, and I can’t confirm or deny that. But for me the SVS subs are just right for my needs. The adjustability via the app is awesome. Very versatile and lets one really dial things in. Also a plus, the SVS are priced right for me. You get a lot for your dough.

I never owned REL. I have one SVS  purchased to add to the existing two HSUs already in the system. If the HSUs ever fail I would definitely go for SVS as replacements.I love that app.Adjusting all of the settings from my listening chair is great.

YouTuber Nemo Propaganda does a good job of doing explaining the differences between the two brands. Might want to check him out. I too had a hard time with REL’s specs as on paper they don’t seem impressive. It’s hard to explain, you kind of have to hear one. They produce bass and have extension but it’s like there is no sub in the room. Just more low end articulation that seems part of the mains. The two brands are just different philosophies. No right or wrong, it comes down to one’s preference.