How effective is Judo for MMA and Self defense?

There are a lack of wrestling clubs in england and in my area. It got me thinking about Judo. I have great respect for the art and what a tough sport it is, With the importantance on the grip on gi . How easy have people found in to transfer to mma with out grips. Is it the same as with BJJ gi and BJJ nogi ? Ive read on Judo forums that it has taken some people up to a year training to hit a throw cleanly against a full resisting opponent. This seams along time , as im using it to supplement my other training . Would it take me getting to a very good level before skills are transferable. I only say this as when learning wrestling techniques in mma i can have success with them right away. I suppose the second question just follows on how have people found judo in self defense situations.