Well I have my new 500D Tow pretty much dialed in now. I just finished weathering it. I have a 5 blade head and scale blades coming so I already have the AP2000i and gyros installed and setup to go flybarless. I do have a bit more vibration showing in the fuselage than I like. It showed up after I attached the rear frame mount to the floor of the fuselage. It is really hard to get to so I was just using the front mount and letting the tail support the rear. The vibration is probably coming from the cheap blades and isn't enough to effect the gyros/flight performance. I will probably leave it as is until I get the nead head and blades.
I am using the HK500GT, Turnigy ESC, HK Typhoon motor and Hyperion and Align (tail) servos. I also have a DeLight led sequencer for the nav lights and plan on installing a search light as well. I use 3000mah and 4200mah 6s and get 5.5 min flights with the 3300 and 8 min with the 4200. It it really stable and smooth. I will get some ff video soon.
BTW the red tubing is to protect the skids while flying from the concrete.