What is the order of rel subs?

And the R series is forward-firing and not ported at all.

Here is the order from the rel website:
Stampede
strata III
strata 5
storm 5
stadium III
stentor III
studio III

That is certainly the order BUT does not include the new B series nor the fact that all of the above except the Stentor and Studio are discontinued in the States. There is some fudge factor, but it is probably about right that the new B3 goes in between the Storm 5 and the Stadium III, the B2 is probably close either above or below the performance of the Stadium III and the B1 is between the Stadium III and Stentor III. Certainly when I spoke with Sumiko about the models, they felt that the Britannia line represented a step forward from the "St" series and indicated that the B1 would stomp all over the Stadium III. I have not compared the two directly, but it seems as though the B1 does not have any advantage over the Stadium in absolute extension (13 versus 12 hz) but certainly has more power with a 500 watt versus a 200 watt amp. Unless the price was great or the appearance important, I think the Britannia line represents a "sweet spot" in the Rel lineup. I believe the B3 was the Absolute Sound mag's subwoofer of the year for 2006 which is pretty high praise for its musicality.

I've owned a Stadium II, a Stadium III and a B1. I sold the B1 and went back to a Stadium III. I think REL, now owned by Sumiko, has gone the home theater route. That may be fine for some people, but I'm a two-channel purist.

As noted here and elsewhere, with the new lineup it's really hard to tell what's going on with the line. It's also interesting that REL's top two subs, the Stentor and Studio, still share the Stadium, Storm and Strata basic configuration. So if they truly believe the front-firing woofer is better, why do their top subwoofers not have that design?

Can't tell you as I am only repeating what they told me. Obviously, they have purchased the company and can sell what they want where they want. If they felt the Stadium III were better than the B series, they could sell it or offer it in addition to the new series. I have heard the argument that the B series might be "less musical" or "more for home theater" but it seems like most who hear the B series like what they hear. I do, and find it quite musical--far more so than my old Velodyne (which I only used for HT), but you have the advantage of direct comparison. Seems like good subs can be build downard firing or forward firing. I wish there were more reviews out there from independent sources. The only one I know of is the Absolute Sound Mag which raved about the B3, but I have not seen a single review of the B1. For me, the measure was whether I could integrate the sub relatively seamlessly into my two channel listening (which I could). The fact that it also works well in my HT setup is a bonus. I imagine the higher power levels of the B series may allow for better integration into HT, but I am not convinced that having more power in reserve is necessarily a detriment for two channel. Still, it is interesting to read of someone that prefers the Stadium to the B1 in direct comparison.