NickG's TX was the nicest, full power, 'sledger' that I've used. Absolutely sublime to shoot.
My old mate Barry bought a Whiscombe back in the 90's to use for FT. My other mate and I had purchased GC2 MK3's - Baz preferred the JW.
I can honestly say there was less vibration and felt movement in the JW than there was in either of our GC2's - but the JW was a pig to operate. Lumping it around a thirty shot FT course and having to prime the thing twice for each shot was akin to going to the gym.