Been playing bass for over 30 years now and in that time I have occasionally tried a few other brands. While some were not overly disappointing, I still found myself going back to the Ernie Ball's.
First off I believe strings are a personal preference thing on a tactile level and can also drastically change the sound of your guitar.
For me the strings work on both levels, feeling smooth and comfortable to play with a fast response. New strings always sound too "jangly" for the first few hours, but after the EB's settle in they give a rich full thick full bodied sound through the right amp. I predominantly play a Precision Bass through Marshall amps and would use no other strings on it.
With Ernie Ball, the bass string prices are a little strong but quality and reliability have never been an issue. At times I have left these strings on a bass for several years and they continued to sound shockingly good.
The only way I think they could possibly be improved was if they came with silks on the ends to protect the tuners a bit, but this really is a minor detail.
All said and done, in my opinion they are the best out there and so long as they don't change, I will continue to use them in all my bass work.
Very highly recommended.