As far as rideability goes I think the Monster 620 is a very good bike to start with. The Seat is quite low, and even myself, with a 32″ inseam could easily get both feet flat. The seating postion is fairly straight up, and although I wouldn’t say it’s exceptionaly comfortable it does make controling the bike quite easy. The power is not overwhelming, only around 50hp so similar to my GS500, and it comes on quite smoothly. I found the clutch to be a little stiff, but not horrible.
I think the only downfall is cost and maintenance. However, if you need to ride something different and have money to burn, why not.
I haven’t ridden the 695 or upcoming 696 so I can really comment on them. Specs show about 70hp…on par with an SV650, which is recomended as a starter. As such, I think if you are familiar with the basic controls of a motorcycle, it wouldn’t be the worst choice for a first bike.