I had a great experience myself recently. After over a year of having flatwounds on my MIM Jazz, I decided to go back to roundwounds. On the advice of my guitar tech, I bought DR Marcus Miller lights (.40-.100). My tech's reasoning was that a bass already has a deep sound so there is no reason for a heavy string- a light one should do the job just as well. He installed them and did a beautiful setup, but I didn't care for the strings. They were great for slapping and popping, especially the "G" string. However, I'm a beginner and my teacher wants me to learn to pluck really hard. When I did, there was too much string rattle, even through the amp. Plucking hard even changed the tone of the string being plucked.
I wasn't happy so I contacted Jason at Bass Strings Online and asked for his advice. He recommended GHS Boomers in medium (.45-.105) and I couldn't be happier. They are a bit on the mellow side, which I prefer and have deep,full, rounded tone that seems to suit the Jazz very nicely.
These were probably the least expensive strings I've bought so far. Jason could have steered me to a more expensive set but instead gave his honest opinion, which turned out to be right on. That kind of integrity is rare these days. All that and they got here in only a couple of days. I can't say enough about Bass Strings Online except to say that dealing with them is such an enjoyable experience that I wish I needed to buy strings more often.
BTW, check out the January issue of Bass Player. There is a nice shot of Jason hocking his wares at the most recent Bass Player Live.