Back in Jan 2008, I purchased two 533-T's and a 533 VAC and paired them with an Onkyo 605. I've thoroughly enjoyed them in my apartment so far. With a tad more money in my pocket, I want to round out the rest of my system. For the sub, I'm attracted to the LFM-1 Plus/SMS-1 deal going on over at Outlaw (instead of getting the bravus 10").
The one part where I'm getting stuck is what to do for the rest of the 5.1 setup. One intended use of the surround/rear is to have the option of using the Zone 2 feature of the reciever and using the the rear speakers for playing music from my Squeezebox Duet when I'm playing a game where the soundtrack isnt the best. The other obviously is joining as seemlessly as possible into my current speakers to create a good 5.1 environment.
The question is would the 5B's be a good option for this role. I would imagine that fitting in the 5B's should do alright even with the 533's being a revision behind. I have read from other forums that the 5B's don't have as good base response and thus need a sub paired with them to be good at playing music solo.
I've also checked out AV123 ELT525 and Monitor Audio BR2 among others (which I can't remember off the top of my head)
I think for what you are trying to accomplish the 5Bs are your best best. Sure they don't have tons of bass, but with 75 Hz at -3 dB they are no slouch either. They don't have as much bass as your towers, but when you are using them as surrounds you won't need much low end anyway. Since the surrounds play a more supporting role in 5.1 set up I wouldn't worry about them not being a perfect timbre match with the 533s either.
Lots of people use the 5Bs for music in smaller rooms so I think they'll fit the bill for that use too, and it sounds like you don't have unrealistic expectations for them. If they are located near you, I think you'll find they are more than adequate for occasional music listening when you are playing a game.
Just let me know if you have any other questions thanks!