Vtouch Jr using AC motor
should be almost zero maintenance as ALL AC motor is brushless.
this one tried and tested legendary blade design (also used in Sensa).

For the Alpha AX60-5B 56 its using DC motor
DC motor can come in brushless or brushed model - you need to check with Alpha to see if motor is brushless or with carbon brush as they didn't explicitly mention.
I'll assume the Alpha Natural Wind = yuragi mode.
Other than that, DC motor save power over AC fan, although it also depends on usage pattern to be noticeable (whether run as per ST testing or just minimal use few hours here n there only)

Make sure the fan hook is long enough to support it. Initially mine was too short(can fit in kdk sensa4) I had to extend it to install thia alpha fan. You may refer the guideline in their site.

Compared to kdk sensa 4 the wind is not as strong and making louder noise.