I haven't travelled long distances on my personal car. But let me share my personal experience:
This January, I visited Highland resort, Golf and Country Club with 04 family members.
I own Toyota Passo, 2013 model and by that time, it was around ~32,000 kms driven. AL HAM DU LILLAH I didn't face any issues, either going uphill or downhill.
But yes, at one of the very very steep slope and a sharp turn, near Highland club, I observed some CVT missing. I had to climb up from a fully stop position and it was like, car going in the backward direction very very slowly, instead of forward. The gear was either S or L. I do not remember exactly. But, I managed to take it to the top, without any burden on the engine, it didn't had to struggle to climb up.
I personally think, comfort wise, Automatic and CVT transmissions are Good as compared to MT.
Control wise, Automatic is the best choice else if in MT, you will have to continuously keep a full grip on handbrake, gears, clutch, and after sometime, you will start feeling exhausted and may not be able to enjoy the views and ride.
Reliability wise, MT is excellent choice.
Well, it's a bit off-topic; but Could someone tell me why that happened, that the car felt going in the backward direction?
Was there any fault in my driving habit?
(I tried to drive with extreme and utmost care, without jeopardizing anything)
Or CVT is to blame? That it's belt couldn't take that much burden?
(If Yes, then CVT is a big Question mark for driving in hilly areas, steep slope roads with passengers and luggage on board)
What to do if such a situation arises?
(Passo also has an issue that it's handbrake is also not there. It's handbrake is basically a footbrake, which is placed besides normal brakes lever. If it got a handbrake, then I think, situation could be easier)
Advice from Experienced Drivers, specially having experience with CVT transmissions, is requested please.