Thank for the feedback! So in any case you think that the MEGA+ which comes with 150mm is overdimensioned? However, is unfortunately the only one that comes with the Thanos board. The normal MEGA one has the Arduino included instead.
There is a difference between the two also on the performance/feeling side (i.e. traction loss is better reproduced in Thanos then on Arduino) or just on the future expansion side?
While I cant comment on the Thanos vs Arduino comparison, the PT electronics are pre-defined at the factory and makes setup much easier. There is a lot of adjustability with these systems (understatement!) and it can be overwhelming if you don't want to spend much of your drive time, tweaking. TBH, I haven't really done anything with my Thanos other than update the firmware. It just works.
It's a shame it isn't easier to try-before-you-buy as any motion is a big financial commitment. I'd only personally tried 2 motion systems prior - but fortunately they represented two extremes - a dbox, and a dof reality H3. The doF was a lot of fun with dirt where you are really thrown around like a fairground ride, but was also noticeably 'loose'. The dbox movement was extremely modest by comparison - but clearly responsive and controlled even on my very brief trial .
The 'less is more' mantra applies more to the quality of the motion - i.e. quality over quantity, and having experienced the two, I knew which was going to provide me with more long-term satisfaction. Again, I only have limited experience of actuator systems, but the PT is proving very satisfying. Much of the difficulty is finding the sweet spot between normal movement and extreme movement during a crash (AKA Spike) . Personally I find pitch, particularly braking being the most immersive motion cue, and the one where I want to have the most motion - but as soon as you have that maxed out - god help you if you have a big off! I think this is one of the reasons the dbox is so revered, as even extreme movements are pretty tame! I'm sure there is still plenty of adjustment I could be doing to improve the experience, though for now I am happy (for the most part) just getting in and driving with motion set at 30-50% max.
IMO Traction loss is not particularly well simulated on a 3dof system, though I would suggest front mounted tactile transducers will provide faster cues for a significantly lower outlay. Combine this with FFB + VR and as far as I am concerned, there is plenty of immersion. If you think you need more than that, you need to get to a race track as I know you will be spending enough to buy a real race car