I think the 48s are great. I have a 4", 6" and two 8 3/8". The older 8 3/8 (1959 no dash) is accurate to the extreme. The newer of my long tubes has the optional LR cylinder. I haven't had the opportunity to put them up, head to head yet. And no, I don't see them for sale as often as many other models like the 17s and 18s.