Advise on new hardware, having frustrations with RTL

Hi there. I know this forum area said NOT to post on alternative hardware like Multiwii, but my real question is more in regards to purchasing a real APM board instead.
I got the Multiwii Pro with MTK GPS from Hobbyking, I’m a software developer so loading it up didn’t seem like a big deal for the savings. I had NO idea about all the tuning, etc involved. So, in the end, I thought I managed to get it tuned (running MegapirateNG 2.7.x). I’ve successfully flown it about 10 times now, flys great. However, I have attempted RTL to test my failsafe 3 times now, the final time resulted in a crash that’s going to cost me $50 or so (probably fairly normal in the beginning, so ok).
So yeah, flies great. I have RTL as my third flight mode, checked GPS lock over bluetooth on phone, checked failsafe on Mission Planner. All seems ok. First 2 times I tested (just going into flight mode 3) quad seemed to just pass by home spot and keep going. I was able to flip back to stability mode and fly it back home. Today I tested again, let it go a little longer thing maybe it just has to adjust. It seemed to start to circle this time like it was trying to get itself to home, but after 1/2 circle just took off in original direction, I tried to switch back and take over, it started to descend, I full throttled it and still it came down and landed hard breaking arms and such, still plenty of battery.
This brings me to my question. I suspect this Multiwii with ported Ardupilot is the culprit here, I’ve also not gotten the numbers I’d expect in my PID’s. I’m perfectly willing to purchase a real APM this time, especially if I get 3.x and auto-tune. However, can someone confirm this is NOT an Ardupilot problem and RTL should work just fine first? I don’t want to get stuck again with something that is not working out. I like the idea of the Ardupilot still and the power it would give me when I get better, but my neighbor has Naza and RTH on it never fails, I’m frustrated. Thanks.

One of the big things I like about the Pixhawk is the on board flight recorder. This black box tells me what happened. I use RTL often and it works ok.

These functions rely on a good GPS and a calibrated compass. Your incident looks like the compass may be off as its searching for the spot to land. It may have switched to just land where ever it was so you needed to switch to another mode to gain throttle use again.

These are complex control systems that just don’t takeoff and land.

Mike

Thanks. I thought about it more too and we’re talking older, ported Ardupilot vs new and “built for”. I’m going to stop wasting my time with the Multwii and get an APM, I just hope it works smoothly and I shouldn’t have gotten a Naza! ;0