If you can still get them, yes. They are now considered a "classic" product. The voice matching is still close enough to the newer models so that the soundfield is still convincing.
Of course, the newer horn in the RB81 or RB61 would be a "closer" match for your mains.
I tend to prefer bookshelf for the rear, but there is always the RS42 or RS52 if you prefer a specifically designed rear speaker. My only experience with them is a pair of not Reference, but Synergy SS3 surrounds I bought a few years ago (still have them, but moved them to the bedroom). I could never quite hear the supposed benefits of that WDST design. I don't know what the new ones are like, but the older ones I have produce a more "diffuse" sound than I like (which would be fine if I just listened to HT, but since I have a number of SACD and DVD-A discs, I need somethings with better localization--thus, the bookshelves).