I have two pairs of the RS-3s. I think they're as good a side surround as you'll find anywhere. I haven't had any issues with them. I have mine mated with Kg4 mains and KV3 center. The entire system sounds great, no complaints. Another surround you might consider is the Emotiva ERD-1. They are on sale right now for $249/pr free shipping. You really can't beat the deal. Check the net for reviews. I haven't seen anything bad written about them. If I were in the market I'd get them without a second thought. Given the choice between the two, I would get the ERD-1s.
No they don't come with a center channel. Emotiva's least expensive bookshelf speakers ERM-6.2LCR are $199/ea. On sale from $299/ea. I purchased the ERM-1s during their closeout some time ago for $149/ea. The 6.2 have 6 1/2" mid/woofers instead of the 5 1/4". I fully recommend the ERM-1s, so it would be a no brainer recommending the 6.2s with a little more bass. Construction and finish are first rate. For $849 you could have the three fronts and two surrounds. Excellent price for this high quality speaker system.