3 60" TT. 2 52" S TT. 1 36" Encore walkbehind and one Lazer X 60" serve me well. I use the walk behinds 95% of the time and use the Lazer on big lots. Only thing I would like to change is the Lazer to a 72" and make my 36" an Exmark. But its okay, I only use the 36" on around 20 back yards and haven't personally used it in probably 9 years...
I've got tens of thousands of hours on walkbehinds with velkes personally and have no issues. In fact, I don't like the Lazer because even with the cushy seat, its not nearly as comfortable as a velke with good bushings in it. Maintain your velke and keep it tight and it won't sway side to side and twerk your knees.