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.
Ike