Went from 45 to 52 not long ago, and love it. The 45 had very stiff spring that caused me to have nothing/nothing/big jump movements in the center - the 52 is silky smooth and very sensitive.
I use pedals because I twist accidentally all the time with twisty -- and I found the rocker on the 45 to be all or nothing, too hard for fine control.
HOWEVER....I really recommend the extended warranty. I've had 2-3 X45s and 2 X52s in the last 18 months. The first X52 I took home lost its up on hat #1 in a week. The others went when a hot got spotty, and since i had teh warrantee i just popped the stick in for replacement-- coulda lived with it if i had to.
I absolutely LOVE the 52, and the second one has been fine for the month I've had it. My hit% jumped about 30%, (but the 45 may have been hindering me mmore than the 54 helped me).