5x7 was such a nice ratio, I went out a bought a Ritter 8x10 with a 7x11 back last year and haven't looked back since. The Ritter weighs in at around 6.5 pounds, so weight is actually the same of less than my old Burke & James 5x7. It is 'larger' than the Burke & James, but I have not found it to be an issue, plus the 7x11 gives me that extra format that I really prefer (it's like a mini 12x20). For lens, I use 240mm Germinar, 300mm Fuji and 450 Fuji all in a Copal No. 1, so they are all lightweight.
See my Rambles for more information and my impression after using the camera. If you find the 8x10 fits your vision, it's wonderfull (not to mention that it is fun to contact print 8x8).