Leg grabs have been removed from judo which seriously reduces it's effectiveness in MMA. I think it can still be useful from the clinch as a lot of the throws can be adapted for no gi situations and it can be very effective against people who have good takedown defence.
However, I don't think it's the most useful grappling style for MMA and is far more suited for self defence. Double leg takedowns are great one on one in a cage but are very risky on the street where you really don't want to be rolling around with you opponent. In that scenario an high impact throw like uchi mata can be lethal and most people wont know any of the counters so you shouldn't have to worry about that.