This is a little late but i'll just throw my opinion in. I'm an avid 5-stringer. Have been using it ever since i threw away my TGM 4-string. My first 5 string was a Hamer Cruise Bass. Amazing bass man.
Here's a tip on getting 5-strings. Because of the lower spectrum that a 5 string gives, it's very very important to hear out your B string because if you get a bass that has a lousy and muddy 5 string, no point, myself get a 4 string right? Also at the same time you have to understand your scale length. Most basses out there are around 34" but some manufacturers do have 35" scales specially for 5th string to combat that floppiness that you get when you play. I'm thankful for my current 5 string, a Fender Warmoth, nice and tight when you play it low. If you are looking for one you can try Yamaha's TRB series, nice, but modify will be nicer, trust me, their stock ain't that nice. Their BB series are nice too, the 5th string on the BB, even though it's a 34" is amazing.
Also Ibanez's BTB series. Very tight low B string. If you have a bit more budget, you can try either Ernie Ball's Musicman or Lakland's 5502 series. These two basses have legendary low B strings that players covet, macham like playing your E string like that man.
Also like other people have mentioned before, you have to take into consideration of what you use your low B for, for me i'm using it for alot of transitional parts of songs when it needs that "oomph" and also for slower songs. It sounds really nice when everything is quiet, provided that your low B is nice and clear lah. Yeah, that's about all i have to say.