I've recently started playing with a pick after about 12 years of finger style and slap.
The sound you get is totally different and the whole feeling of playing bass changes, I especially love the sound of palm muted picking, it sounds amazing for funk.
If you don't love it though I don't see any reason to practice using one.
The thing that made me want to keep practicing (it sounded rubbish at first, like all techniques in the beginning) was this one YouTube video where the guy plays a similar Bassline on different precision basses, but also using different playing styles (you may have seen it).
After seeing that I just felt "I want to be able to do that!" and that video has kept me going.
I also bought a precision as well, no regrets.
Pick at 1.54
[media]http://www.youtube.com/watch?v=rgzD3vcrExE[/media]
This guy, Patrick Hunter, is also a phenomenal pick player.
[url="https://youtu.be/fPWjxsVt00Y"][media]http://www.youtube.com/watch?v=fPWjxsVt00Y[/media][/url]