I know there are a lot of Behringer owners on the forum, and the 2031As are also a possibility since I don't really know how much "better" the higher priced model might be.
I just added a pair of Behringer 2031a monitors to my HW rig. The clarity is amazing compared to my HiFi full range speakers. I'm still using both sets however. I think the 2031a is favored here as they are a good fit of sounding better than cheaper brands or even competing brands at their price point. I notice they can handle a sustained organ tone without issue and offer a powerful bi-amped design. With more expensive monitors you start to get into diminishing returns with regards to HW.
One thing I'm impressed about is this design has been around for awhile as Behringer doesn't change it or the specs every 18 months like other brands to help generate a marketing buzz (i.e. M-Audio). So if you are like me and planning to slowly add additional pairs to build a multi-channel HW setup, I'd feel comfortable knowing I can order these identical models at a later date. Oh yea, I picked up my pair on Craigslist in mint condition at a great deal.
Not to muddy the waters, another HW friend turned me on to the Monprice website. They have a pair of 8" studio monitors with close specs to the Behringer 2031a, just not as powerful. They ran a one day sale on these in June and he picked up a pair for just under $200 (plus free shipping)! He is very pleased with the way they sound. They offer a matching powered sub-woofer as well.
http://www.monoprice.com/Category?c_id=115&cp_id=11504
Danny B.