I have used both brands plus Rimowa quite a bit. B&R has the advantage of the lifetime warranty, and it's the only brand of the three I've never had to get warranty service on, although the problems I've had with Tumi and Rimowa have been relatively minor in the big scheme of things. With Tumi, if the repair can't be handled in store, you'll pay for shipping after the first ("worry-free") year. I've never had to pay anything for Rimowa warranty repairs since I'm close to a designated repair shop, but shipping to the shop would be at your expense.

My experience with B&R is limited to the Torq and Sympatico lines, which are all polycarbonate spinners. I see you prefer two-wheeled carry-ons but suggest you try out one of the B&R hard spinners (both versions of the Torq are currently well under $300 from Amazon). IMHO, once you go spinner you won't go back. They're just so much more maneuverable (particularly down narrow airplane aisles) and easier to push alongside you that it's worth the minor loss of capacity. I'm not a fan of B&R's "outsider" handles on the soft bags given the wasted space, but it's not an issue with the hard cases. B&R and Rimowa have very smooth-rolling, robust wheels on the spinners, as they're larger than on Tumi's spinners. Tumi only switched relatively recently from single to double wheels for their spinners; the double wheels roll better but still not as well as B&R and Rimowa's larger double wheels. Any polycarbonate bag's surfaces will get scuffed, especially if it gets checked (and the scuffs seem to be more visible on Tumi and B&R than on Rimowa bags).

I wouldn't lose too much sleep over whether your bag is a half inch over the airline's specified size. In reality they almost never check for size unless your bag is visibly larger than a normal carry-on, and even the sizers are larger than specified. B&R's hard spinners all fit fine in my experience - it's Tumi's larger Continental size (and Rimowa's wider, squatter carry-on size) that can sometimes cause problems. You do need to be more careful if you fly often on small regional planes or with carriers (typically low-cost carriers) that are strict about carry-ons. But with the former, even smaller carry-ons will need gate-checking, and with the latter it's more often an issue of weight rather than size.