Sorry I can't offer any advise :-(
But I am interested in your findings as I just bought a TL521 as well with all the bells and whistles. Brushless motor, anti backlash screws, R8 spindle, 4th axis ect...
I will see it on Tuesday, but won't have my end mills till later in the week.
Any helpful advise you could relate would be appreciated :-)
P.s. have you added other software other than the Mach3 and CamBam?