I have heard the R 909 once and it was in a controlled demo setting and for a short period of time (less than 15 mins). It is EXTREMELY room dependant. If you have a dedicated listening room where these can be brought out from the wall or a large open space that can accept these then I say go for it!
In Europe (and I would imagine here in the US soon) Jamo has a smaller version, the R 907, that uses 12" woofers instead of 15" ones and is thousands less. If for nothing else then a statement piece, I'm really trying to find a place for the R 909 in the new showroom I'm designing and it's becoming a struggle to integrate it in to any of the spaces properly. I'm about to just give up! This is a much different speaker than the B&W 800 pieces and it would be tough to compare them other than, "Which is better", and only you, the listener, can determine that. The R 909 provides a very unique
At the price of the R 909, which is $15K, I would say that if in-walls are a possible option (don't know your situation) I would strongly consider the BG Radia R-800 system over the Jamo R 909 if you’re looking for Hi-fi musical performance. While the BG R-800 retails @ $18,750 a dealer should give it to you at $14K or a little under. I assure you that a dealer who's interested in a long term relationship with you as a client will be able to do that price, no problem. The BG Radia speaker line, in general, is quite possibly my favorite loud speaker I've ever heard from top to bottom and I recommend them to clients & hobbyists wholeheartedly. If ultra high end music or HT were my goal and I could install absolutely anything I wanted, a pair of BG R-800 would, without doubt, be the back bone of MY system (I would add a pair of JL F113) granted I had the physical depth in my room. You just have to sit back from them (large room) a bit. But when you do they provide an entire wall of sound that’s just enveloping. I've never heard anything even close and I mean that.
http://www.bgcorp.com/productDetail.php?id=58
Another hi-fi speaker that offers top-shelf performance is the RBH T-30LSE. I won't go into these much because AH did a review on them just last year.
Another option to compare to the 800 B&W series would be the Canton Vento line. Again, as good? That's up to you, but the Vento is a very nice speaker that I think would not be out of it's league in the company of the 800's. The reference 5 MSRP is $10K and it's excellent.
http://www.canton.de/en-produktdetail-vento-ventoreference5dc.htm
The only time I've sat down and really had a listen to B&W 800 series was just this past Fall. The set up was actually a "Reference" theatre at another hi-fi shop. They were running 4 B&W 800D with the HUGE matching center, and the Ds8s surrounds for channels 6 & 7, and two JL F113 subs. It was atrocious and I was extremely disappointed, but I don't fault the speakers in the least. I fault the dealer. These were in a 16x16 room that had over $150K in gear in it and was quite possibly the 2nd worst demo I've ever seen &/or heard. The 800D's were all four pushed into the extreme corners of the room, surround backs were directly over head, nothing was set up correctly from a placement or room stand point. An absolute waste!
I'm sure the B&W 800 series is an amazing line and worth spending a good amount of time auditioning. Just make sure to find a dealer who will put them in a realistic environment where they can function properly. The same goes for the others I mentioned above.
I usually try to not comment on products or concepts I don't have strong experience with, but in the case of the OP's question I think it's going to be tough to find many folks that have heard & compared both speakers in question, particularly the R 909 which is a very very rare piece. I tried to contribute what I could. Sorry if it wasn't much help.
Good Luck!
