mk2 or mk3??. Don't care "subjective" audio quality

[edding]

Sorry my bad enlgish.

I'm thinking on buy a motu828 mk2 or mk3 and i don't wich one is better to my requirements.
I'm not interested in audio quality difference becouse i know they can't support a blind A/B experiment about AD/DA converter loop. maybe 1 of 30 persons can feel some kind of difference between both preamps (not converters), but they can't know what sound better, the only know that it sound different.

I'm interested in what i think is the most important question: Stability and easy use.
I only want a guitar mixer rack and audio interface function. I don't want FX.

Guitar mixer rack:
I see there are 7 digital pots in mk2 and only 5 for the mk3.
¿Which one have an easy and quick unplugged mode use for use like a digital mixer? ¿Can the mk3 operates better with less pots?
¿Which one have better stability in unplugged mode for a live performance?

Audio Inteface :
¿which one have the best stability drivers?

Thanks a lot

[1nput0utput]

In my opinion, the 828mk3 is easier to use as a standalone mixer when you're controlling it from the front panel. Yes, it has fewer knobs dedicated to these features, but the way that the user interface is designed makes controlling the mixer functions much more intuitive. You mentioned that you are not interested in integrated effects processing, but it certainly doesn't detract from the experience of using the interface to have them there. With an 828mk3, you'll know that if you ever need an extra EQ or compressor, you can easily insert one on any input without reaching for another stomp box. Both models are very stable in the standalone mode, and they both use the same driver with Mac OS X and the same driver with Windows XP or Vista.

[edding]

thank you for the answer. It's great to know mk3 has a good user interface throug digital pots
I want it to mix guitar signals (axefx and MIDI_guitar_synths) in a live scenario. The XLR output of the mk3 is a very good advantage on live performances.
mk2 cost 450€ second hand (discontinued) and mk3 cost 700€ on european stores.
It's a important price gap (nearly double). i must meditate.