From a few vids I watched, it seems a bit louder than the Bafang. All my hunting spots are quite a bit away from where'd I park so it isn't a big deal.I agree with every thing your saying. Lots of people go a thousand miles with nothing done to the bbshd itself. I went with that motor because of the track record. im sure people wreck their cassettes and derailers especially on bikes that come with cheaper drivetrain components. it has a lot of torque and chain alignment is pretty important to avoid damaging things. Theres other options i could have picked but i will wait and see how they do after 5 or 6 yrs on the market. lots of replacement parts for the bbshd if anything goes wrong. I programmed mine when i built it so its not jerking on my deraileur or cassette if i go straight into throttle and i have a cut off switch (horn) i wired to my display that will temporarily shut off power for shifting until i release the button. The gear shift sensors they sell dont have a long enough cut off for this IMO . I have a decent cassette on the back (but will probably switch to a box drivetrain shortly for the same reasons your talking about), a beefier kmc e chain and a 30T chainring on the front so its not working the motor as hard as the 46T. If im in a granny gear and i know its going to put a lot of torque on my rear cogs i am not usually going to be on 5 power. I definitely ride more in the style of 1 and 2 power only so it works for me. Ive definitely played around with it to see what its capable of but im not riding it wide open throttle from dead stop all the time. Even if i go from dead stop using throttle its easy enough to program so it doesnt just rip into full power and break something.
I dont care about speed too much. it goes plenty fast offroad for me about 18mph or so in 5th gear on full power and the biggest thing i wanted was something quiet. I have no idea what the XD motor sounds like (not a lot of reviews on it and its hard to get a feel for noise on go pro cams) but i know CYC were a little too loud for what i wanted my bike to do. You literally cant hear it over the tires. The new CYC Photon is apparently pretty quiet too but i have no idea how dependable theyre going to be.
I think Biktrix has a good thing going. If i had the money maybe i would have gone that route. I had to keep my build around 2k so its what worked for me. One thing i would add on that XD bike would be a suntour suspension seatpost. Its been my favorite add on so far for the money spent. I think i bought mine off their website on sale for about $80 shipped.
I currently have the Coast dropper/suspension seat post on my pedal bike and it's a must have. You can adjust the air pressure for how much suspension you want. It really takes the sting out of those harder impacts.
This dude on utube must be the only guy who bought an XD. In this you see the speed, noise of the motor.