I have Tyros 1 which I keep as a backup, I use the G70 for all my gigs both live with manual bass and as an arranger.
I feel overall it is a professional looking and sounding arranger. It does not have all the styles I would like and I'm gradually building up a stock of my type of styles. I did not feel good about taking the Tyros out to a gig as I feel it is basically a home keyboard and does not look professional for a paying job..
I think from day one we are all hungry for more/better sounds but realistically we never had so much sounds in our lives. Anyway we usually end up playing the same 7 or 8 sounds we like regardless.
The G70 is heavy yes but to me it is a good sounding professional keyboard and the weight issue would be the last issue that would come to my mind.

Frank