I know my area is a bit different than most; most of the venues I play original material are located in Manhattan. I would say about 95% of these venues have a bass backline. If the venue has a backline, I use it. I walk in with a gigbag and walk out with a gigbag. My kind of gig, but that is my personal preference. Now, I have some fantastic gear that in a world where roadies were abundant I would prefer to use. However, I find the majority of gear more than adequate to perform the task at hand (especially when I am going through sound reinforcement). How about everyone else? Also, as a side note; I find it amusing that one of my current drummers insists on bring all of his own hardware when he plays a show, irregardless of the availability of backline hardware. It's his cartage, so it isn't any skin off my back. Additionally, both of my current guitarists also insist on using their amps, again, irregardless of the backline. While each amplifier does sound different, being a tone freak at a small club makes me giggle. Is it just me?
I have always used an available back line, and was only disappointed a few times, to be honest, in the quality of the gear. Usually the gear is some indestructible Peavey or an old SVT warhorse , and certainly servicable if not my first choice. The killer part is when there is abackline available at an open mike and some guy decides to drag his combo on stage-- for 2 songs!!
I don't trust other people's stuff. So i always bring my own. Before it was a pain dragging around my TNT, but with the new rig it won't be an issue.