I'm going to have to voice my emphatic support for changing out the Low B for a High C. I have only one five string bass, but I struggled for YEARS to try and get a good sound out of the B string. Other than dumping more compression on it than I feel any bass should ever have on it, I wasn't able to do it. I had my bass set up several times and I still noticed prominent rattle of the B string when played open or lower than the 3rd fret, not to mention fretting any note on it caused more blurb and rattle than note definition.
With that said, here's my advantages towards switching to the high C. It can completely change the way your bass plays. After switching, I realized the reason my bass felt clunky was because of the thicker strings. Simply by putting .020's worth of space between the strings made all the difference in feeling comfortable. Also, the change in the degree of tension can change how well your bass stays in tune. When I set up my bass in the EADGC configuration, and since then, it has been my most reliable bass for accurate tones.
I have also only lost one note in the process. I do a lot of tuning changes, most notably tuning my E down to C. Trying this before with the B string would have been silly, but on the few occassions I need to zone out and rock a bunch of low notes in a row, I've been able to do it. Also having the Tenor "ADGC" setup below it makes it an interesting tuning for open bass playing. My open C sounds infinitely better than the 1st fret of any 5 string bass I have played. I played over 100 5-strings looking for the one that I had, and even then I changed it.
I'm sharing my experience just to give people ideas. I understand why many bassists want the low B, I just don't see the practicality in it especially if you bought a 5-string for under 800 dollars. The pickups won't be a high enough quality to accurately capture the lowest frequency, B. Sorry. I've played every 5 string made by Ibanez, Yamaha, Fender, Warwick, and the other big league instrument builders, and none of them could get a solid B tone to my liking. Maybe that's just me and I'm asking too much out of a warbling .120-.140 string but you'd hope they were designed to work in the first place.