AJR, whereabouts on the Wye will you be fishing? Where I occasionally fish it (low down, below Monmouth) a 10/11 rod would be way too much.
There are very few places on that beat where you need to cast 30yds. Moreover, as you probably know, the bulk of the Wye fishing is now for summer fish; the spring runs of old having all but disappeared. And unless you're fishing it early in the season (ie up to about mid-April) for one of these rare springers you probably won't need more than a floating line. In typical summer conditions much of the river is very flat, glassy water, and a #10 line creates a good deal of disturbance. I've mentioned my feelings about line disturbance here before. Having recently been fortunate enough to fish the Spey for a few days, I can see that on a classic big Scottish river there's little problem with using a heavy, thick line even in lowish water conditions. But believe me, on much of the Wye (at least in its lower reaches) a heavy line will really not help your catches during the main season. I use a 15' rod because I like the water coverage it gives. But I team it with a #7 line. I could manage it quite well well with a rod a foot shorter.
I've never fished the Usk, but I think it's a smaller river than the Wye. Don't know about the Tyne at all.
I've no doubt that the 10/11 may be a better casting rod, and would also be better for using sunk lines or heavy tips. But I think you'd find yourself overgunned on the waters you mention.