I have a compatible battery, and it's just fine.
But if you are getting a compatible battery, do check the specifications carefully and make sure you are getting like for like. Then you shouldn't have any problems.
Many compatibles are cheaper because they have lower capacities and outputs. They will still work, but just won't last as long.

I have a 50-135 and am very impressed with it - a wonderfully sharp lens. I think it's a good choice and you will be pleased with it.
I shall probably get the 60-250 next, but as another user has commented you can crop images taken with this quite heavily, so I don't miss the extra range too much.