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!
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!