Unfortunately I have no experience with the Ehrlund or Stat-B-Vintage, however I have used the Stat-B-Select and the DPA 4099 quite extensively.
I had feedback problems with both. More-so with the DPA.
If you think feedback may be an issue for you in the types of venues/rooms you generally play, I would immediately end your interest in the DPA.
Don't get me wrong, the thing sounds great and I achieved a beautiful arco sound from it, but in the end I gave up trying to fight with it's desire to feedback in almost every situation where I was on stage with other instruments. It just became completely impractical.
The Stat-B-Select I used for some time.
The arco sound was excellent, and I know Barenaked Ladies' double bassist, Jim Creeggan up until recently also used one of these Schertler's for many many years on tours throughout the US, Canada, and the UK, solely for its impressive arco sound, but it can also be prone to feeding back somewhat, and I found the pizz sound a bit flat and lacking enough about it for me to really continue working with it.
I wanted something with a bit more punch for pizz work, so got shot of the Schertler Stat-B after 18-24 months.
I now have a Wilson K4, which for my bass, is just outstanding. Not once have I ever experienced a single element of feedback with it, and I get a sweet pizz sound. The arco sound is not quite up there with the Schertler or DPA, but is still more than capable of delivering to a great level.
Creeggan has also notably switched to a Wilson K4 for both pizz & arco.
I hope that helps somewhat