I've been playing with the Millenium MPS-750X for more than a year now. I started from zero, no previous drumming experience, and this kit served me extremely well in my beginner journey and is still serving me very well to this day. However, I need to highlight few pain points which could definitely be improved:
1. The kit's default settings aren't good for everybody.
Over time I spent countless of hours understanding and tweaking the Advanced settings to get a good response from all the kit's components, so that playing feels nice and natural. I also changed them as my playing style evolved, and you might have to do the same.
2. The kick pad is just bad.
The sensitivity is very low, you have to stomp very hard to make it trigger, encouraging bad technique. The reason is the badly designed piezo sensor and/or bad choice of materials. I fixed it by disassembling it, removing the piezo under the foam and bringing it in direct contact with the mesh. But I was never able to get a good feeling out of it. Eventually, I bought a second hand kick pad from Yamaha and I've been happy since.
3. Snare is not great for drum rolls, flams, and stuff that need fast response. However, it's not a problem for beginners. I never had to play these techniques until recently