Not really but nice to have.
Had a D180 with autopilot for the last 9 years and it worked great. I did have it connected to my iFly GPS and my Garmin GNC255 for LOC/GS display and tracking on the D180, but you can easily fly just in a heading mode. I just recently upgraded to a Dynon HDX and the servos are the same. The only difference is that with the D180 you connect only 5 of the 7 servo wires. Keep the extra two wires, do not cut them, because if you upgrade later on, those wires are used with the newer system. Save yourself some time and make your wire harness with 7 wires now so you don't have to redo it later. I wish I had. You can control the autopilot through the D180 but it is easier to use an HS34 or an AP74 controller, neither of which are made anymore.
The only issue I ever had with the D180 and the autopilot was a tendency to wander left and right on a course line. A little dance if you would. Nothing too bad but compared to the newer HDX that one is rock solid. Tried to change settings to alleviate this but no joy. If you do connect your D180 to a GPS or even a VOR, the autopilot also does not lead the turn like the newer systems do. You'll overfly the waypoint/fix every time and overshoot on the backside. I tended to prefer using the heading mode to stay on track and that would also hold rock steady instead of the slight wandering in track mode.
YMMV