I learned on a larger bike than most on this site and things have worked out well. Mine was 100lbs lighter, but then again I had the clutch to learn so that probably evened things out.
The reason for my response was more a feeling that it’s best to learn on a geared bike because that is what most bikes are and you’ll be limited in your choice because of a limited skill set. Personally I’m glad that I learned without ABS, though it would certainly be something to look for should I be in the market for another bike.
I think the Mana is a beautiful bike. Though not a typical choice for a beginner, would the 10 or so HP and 100lbs that it has above an SV650(I guess the largest bike that is generally recommended as suitable for any beginner) be offset by not having to learn to use a clutch? Since I’ve never ridden one I can’t give an honest opinion. All I can say first hand is that learning to ride an automatic, in my case a 150cc scooter, was an excellent first step on two wheels.
Other factors would also come into play, your age and maturity level, where you’d be learning(urban, suburban, rural), do you have someone to ride with or would you be on your own, your physical size and condition(you’re talking about a 500lb+ piece of machinery that I guarantee at more than one point you will be trying to catch before it hits the ground), etc.