REL strata III vs Spendor Sub 3, which to use with S3/5?

I doubt you'll find anyone who has compared these two subs, which is what you requested. I, like those above, have had great success with REL products. However, I find the Strata III (which replaced a Storm II) to be superior to the vented design of the Storm. It is tighter and more controlled, although not quite as deep (although you must consider your room size to determine if this will make a difference - most mid-sized rooms (say, 15 by 20 or so) cannot support bass in the low 20's anyway, as a matter of physics)). If you're like me, you'll be surprised how low you need to set the crossover to work with a pair of main speakers nominally rated at, say, 45hz. Room interactions often lower this to a "real" 3db rating of 30 to 35 hz. Which means your crossover needs to be below this number. The Strata III starts the crossover at 22hz, so it has plenty of room to match your speakers as they really work in your room.
I would also point out that if you buy the Spendor sub and don't like it, well, good luck selling it. Buy the Strata III and you'll lose $100 on resale, and it will sell in a day.
Good luck with your choice!

To answer some questions, the Spendor sub has a bit more power, 130 watts instead of 100, has a continuously adjustable crossover from 50-90hz [instead of 22-90hz on the REL], has a vented box instead of a sealed box, and costs $1169 instead of $1495 [I think] for the REL. Unlike the REL, the Spendor does not have high level inputs.
Thanks for your thoughts.

Find a recent issue of Listener Magazine. They are comparing a REL to the Spendor (Although a more expensive model REL that you are asking about).

I am using two REL Storm III's with Spendor SP - 100 Speakers, and it is a marvelous match. The REL's were developed with the Spendor's, and the Quad's from past information received.

I believe it.

David

Don't agree with Greenink. I had a chance to compare
Strata III with Storm III A to B and Storm is just a step up. It sounds much deeper and more natural. I don't care what the design is. I got it, upgraded cable and PC and it sounds fantastic now. I should've not say "sounds" because it perfectly blends with mains and disappiars.
REL gives you easy placement and great control.
This is just my experience.
Good luck.

Replacing the power cord with something better on the Storm III will tighten up the bass. The Stratus probably sounds tighter on a quick comparison because it does not go as low, so it does not set off room effects as much. Each REL going up the line is an improvement over the one below it from my experience and from what I have read.

There was someone writing reviews on Audioreview.com that made the same comments about the Storm III and Stadium III not being as good as the Stratus III because of the port issue. I do not agree or believe it, especially considering they feel the Stratus III is a better sub than the Stadium III. But I guess everyone is entitled to their opinion. The Stratus is a great sub; but if you can swing the extra $500 for the Storm, I recommend you do so.

There are reviews on both the Storm III and Stratus III at www.hifichoice.co.uk ---- They liked the Stratus, but felt it did not go low enough. They rated the Storm III their favorite of all the subs they have encoutered. They are a mid-fi and budget audiophile magazine. Mostly stuff under $2000 per piece. I've always liked this magazine. They do not seem to kiss up to companies that advertise with them as some audio magazines do.