Wipr 2 is great! And so is the dev, with who I've talked to before. The difference between WebShield & Wipr 2 is WebShield allows you to specifically toggle on/off which lists you'd like, as well as add your own custom lists. Kaylee (Wipr dev) also has to maintain the lists herself (she sources a lot from other lists), so there is a bit of manual maintenance for her, because Wipr is meant to be an "install & forget" app for the most part. There are tradeoffs that come with this design, for example, all scriptlets (called injectables in Wipr), to my knowledge, are injected as as a content script, whereas WebShield is similar but we inject each scriptlet on demand, cache it (not sure if Wipr does caches too), ensure it doesn't re-inject on the same page (more testing needs to be done with this, and I'm not sure if Wipr 2 already checks for this). That's just off the top of my head.
With that said, Wipr 2 is great and very reliable. If you enjoy using it and it fits all your needs, you tried WebShield and didn't feel the need to switch, continue using Wipr! I'm not trying to conquer the world.