At my 911 service, almost all of the trucks are P/I. Basics are slowly being phased out. The service pays for ILS classes and we expect to have all of our basics transitioned to intermediate by the end of 2011. Those who choose not to go through ILS or can't pass the course will be terminated.
At the IFT service we have a mix of basics and intermediates. Most of the basics are not assigned to ALS rigs unless we are short staffed.
As for my personal preference?
I'd obviously rather have a good partner over a lazy one, but all things equal, I'll rather work with a good Intermediate than a good basic. I appreciate the extra set of "advanced" hands, and our P/I crews work really well together. Most of the EMT-B fire fighters that respond on 911 calls are only used to carry stuff and do compressions.