Another bass player and I spent a few days with the Sound Clip, fiddling with the amount of weights to add and trying different mounting locations and tensions. (FYI it was his personal pickup). The frequency response was extremely uneven, which greatly limited gain before feedback. We found the Sound Clip to be essentially unusable with pizz.
The owner of the pickup bought a Fishman Platinum Pro EQ/DI...the original analog one. It did not really seem to help. I ran the Sound Clip into a Countryman Type 85 DI with 10 Meg input impedance. I tried to tune the pickup with the channel strip on a Yamaha LS9-16. This EQ was set up for four bands of parametric and also had a variable HPF. My point: It's a pretty powerful and flexible EQ. Still sounded awful.
For the record I have a lot of experience tuning upright with EQ, and I can make most pickups sound relatively good. Not the Sound Clip. It seem totally resistant to EQ.
The Sound Clip was replaced by an Ehrlund EAP which is probably the best sounding pickup I have ever heard. The owner indicated he would keep the Sound Clip because of how convenient it was to use on different basses. I believe he wound up selling it fairly quickly though. He tried it on multiple basses and reported they all sounded bad.
I do think the Sound Clip would probably be a bit less horrible with arco...but I still would not use it.
Honestly if John Patitucci can't make it sound good...
I do agree that Patitucci is able to fill out the sound a bit in this video, but he's not really amplifying the bass...in other words, he is not really making the bass any louder than it is acoustically. The negative characteristics of this pickup will quickly become much more apparent if you need to actually amplify the bass.
Years ago I tried a Barcus Berry B3150M. I agree the B3150M is somewhat fragile, and from what I remember the results were pretty similar to the sound clip...maybe a touch better but not much. Although I found the results unacceptable, I reserved judgement on the B3150 as I believe it should be used with a 3000A preamp or the updated 3000AE. The pickup has a RCA plug that mates to the preamp. The preamp provides 1/4" output.
At the time when I tried the B3150M, the bass I was using had a Barcus Berry pickup that looked like three pieces of popsicle sticks permanently glued to the bridge. This pickup also required an inline buffer amp. This was one of the best sounding pickups I ever used, so I did not invest too much time in trying to make the B3150 work. I tried the B3150 because the 3.5mm jack on the popsicle pickup was damaged when the buffer fell of the tail piece. The buffer was held to the back of the tailpiece with velcro.