intrathecal baclofen pumps. pros and cons. does anybody have experience with these?

I was diagnosed with PPMS in 2000 and since then have been on a range of therapies for spasms and symptomatic control. i am currently on oral gabapentin and baclofen. recently it was suggested that an intrathecal baclofen pump would be a useful therapy to me. does anybody have any useful links about this or any experience with this subject?