I don't think it's too early, I am quite sure sure you can use tablet with very good result. All you need is decent CPU and external sound card.
Regarding CPU:
I tested 3 systems with PT.
1.) Old Atom 330 laptop - Passmark score 595
Probably minimum spec you can use, after some tweaking (internal sample rate 24000, max. polyphony 48...) I was able to get fine result for my type of playing (easy songs). However when I loaded more demanding midi file to PT, it just could not handle it.
2.) Lenovo 190 mini PC with Intel Pentium 2127 - Passmark score 1865
No problem at all, it handled even most demanding midi file where PT reached 256 polyphony (I kept pedal down the whole song, which is not normal of course).
3.) My gaming PC Core i5 4GHz - Passmark score 6500 with default 3.3 GHz
Well, simply overkill for PT, it is sleeping at 1600Mhz most of the time.
Now, the important part - EXTERNAL sound card. I use Native instruments traktor audio 2
http://www.native-instruments.com/en/pr...r-audio-2/
Very good sound quality, minimal total latency (about 6ms with all 3 tested systems), very small (you can have it in the pocket). Sound quality was exactly the same on all tested systems.
For 95€ you can't get any better I think. And it has external power input in case your USB can not provide enough power.
So to summarize, try to get
1.) Tablet/laptop/PC with CPU with passmark score at least 1800
2.) External sound card
P.S. Tablet you mentioned Lenovo miix 10 has Atom 2760 CPU with passmark score 679 only - not enough.