You underestimate helicopters, they vibrate, no mater what they vibrate.
Yep, I get it. Cyclic / swash plates = resulting cyclic vibrations. Vibrations can be a major issue in all model types - especially those with large, single cylinder IC engines (regardless of vehicle type).
I've built just 4 helicopters (all proper 6 channel types) over the years - 2 Raptor 60 nitro powered things and 2 electric lipo powered mini helicopters, which I used to fly indoors (inside a leisure centre). One of them I actually still own (it's in a box in my garage somewhere). However, I've had an opportunity over the years to 'operate' some very interesting flying machines.
Back to the case in point - Coreless V Brushless.
I think any perceived performance advantage with coreless servos is now overcome by brushless servos with their increased efficiency, higher power/torque output and longer life.
The death of servos often comes about as combination of zero isolation, incorrect end points, high voltage and excessive shock loads.
The latter would only really occur in a helicopter if it struck terrain, in which case we would normally attribute that to pilot error, rather than servo failure.
Generally, we see people on this forum burning up RTR servos. These servos are invariably cheaper, coreless, digital servos.
Upgrade to just about any modern brushless servo - and the issues tend to go away.
I'm a firm believer in buying quality servos. The difference is perceivable, especially when you are timed racing around on a twisty carpet track. Likewise, you can definitely get used to a 'connected', low latency system and fast (quicker than 60°/0.08s) servos.
Consequently, I am now dependent on 'feeling' what my rigs are doing and the quality of both the radio link and the output of motion are the only way to ensure that 'feel' is maintained across my multiple different platforms.
As you yourself use Express LRS, and I TBS Crossfire (for a/c & FPV drones) & FASST for all my surface stuff, it's really easy to take this level of connection for granted.
I recently tried a bog standard, 2.4ghz RTR pistol grip radio for a TT01. It was laggy and required putting inputs in noticeably ahead of time to avoid constantly hitting the markings.
It's fine for ripping around outside in a parking lot, not so much for threading the eye of the needle in a busy heat!
Again, through preference, I really can't stand Pistol radios. Probably because I have developed strong memory muscle with stick radios over the years since I was 8, but also because they are counter intuitive with my aircraft radios. Opposable thumbs rule!
