I have a Pro 5.0 for the 3650 and it's wonderful. It's a little notchy at first, but once it breaks in it's pretty smooth. Great for bangin gears. With the stock shifter ball it's as qiuet as the stock shifter, but with any aluminum shifter ball you will get the dreaded vibration.
My guess if you find that most people will vote for the one they own. Also you will find that most people own the Tri-Ax, as it usualy sells for less than the Pro 5.0 and is more widely available. I like my Pro 5.0 although the standard handle is too short in my oppinion, the Pro 5.0 with the Tri-Ax handle make a great combination though. Also if you search through the threads you will see that this question comes up every couple of weeks, and you will also notice that fairly often Tri-Ax owners complain of excessive noise, although none seem to mention it in these Pro 5.0 vs Tri-Ax threads.
i own the tri-ax, so im partial. i can however explain it to you.
it is very notchy at first, but loosens up the more it is broken in. i love the firmness it gives to my shifts, great for power shifting and bangin through the gears. i now dont have a fear that i will snap the shifter as i shift hard like i did w/ the stocky. the peace of mind i get from KNOWING 2nd goes straight to 3rd is awesome. i was teaching my sis to drive a standard on my car (bad idea) and she asked where 3rd was, i said "just push straight up from 2nd and it slips right in, no worries" sure enough, she never missed a gear. a lot of people say it is noisy, but the only bad noise i notice is back and forth in neutral which is never done anyway. i have to listen hard to hear noise while im driving, and its hard with the "loud" stock exhaust. plus i kinda like what little noise there is anyway. its a solid shifter from a solid company, and for only $175 shipped to my door, cant go wrong!! i dont know how the install is for a 5.0, but tri-ax was a breeze! took me 2 1/2 hours, but i was being very careful for it was the first install dont to my car, w/ the exception of a K&N. the only part i had to enlist my dad for help was getting the stock shifter pulled off. just pull really hard!!
I may be a little partial to the tri-ax, being that I have one, but I have nothing but praise for it. I had no noticable noise increase at all, but I did use all the factory sound dampers. Its gives you 2 hieght levels and the 2nd one is perfect. Its night and day compared to the stock joke of a shifter, that must have been designed for little old ladys.
After I buy a new intake manifold for my car my next mod will most likely be a new shifter. I haven't decided which one to get. How do you go about installing one of these. BTW ford raised their price from 267 for an intake manifold to 583. Because its a new year. Isn't that bs. Good thing we called them before and they would still honor our price quote.
I vote tri ax.. I have it on my 2002 mustang gt and I love it.. I have nothing but good things to say about. I have driven a couple stangs with pro 5.0 shifters and I didn't really like them.. the triax seems smoother and more precise...
My vote goes for the Pro 5.0, but that's becuase it's the one that I have. I have never used the tri-ax nor have heard any friend complaint about it. Anyone should do fine.