I don't think you can reduce the time-between-royals by 1/50th just because you are playing a 50-hand poker machine. All 50 draws are dependent on the cards you keep in the original hand, which is different from having 50 different starting hands dealt. The cycle time for royals should be less on 50-hand machines (vs. single hand) but not to the magnitude of 1/50th.

I DO like the 10-hand and 50-hand machines however. Less volitility; starting hands perform closer to the expected value of the draw, such that, for bankroll purposes, playing $2.50 per hand on a 5c 50-hand machine is no more exposure than $1.25 per hand on a 25c single-hand machine (re: chances of "gambler's ruin" happening for a given size bankroll).