Don't really understand why any active CW operator would use a straight key, except possibly on SKN for nostalgia purposes.
I use a Brown Brothers ST-A. I tried many before I settled on this gem. It is beautiful and one great key.
The Nye Viking Master Key was the one it replaced. I almost never use a keyer and am thus quite poor at it. With a decent straight key, I can send at least 25wpm comfortably.
I also use a manual can opener (the newer ergonomic type) and drive a car (2010 model) with a manual transmission and hand crank windows. Sure it is more work, but the body needn't atrophy -- i for one am not in favor of evolving into a brain and a finger tip.
I do sometimes get a tired fist now that I am getting older, maybe I will learn to use that pretty Brown Bros BTL keyer