TC electronics works,even the clip on,tested in a noisy room.
If you are getting the clip on get the unitune,the poly tune mod is not for bass anyway.
Well, I'm using the Korg Pitchclip 2+ and it's a piece of sh*t.I've been using a Peterson Strobostomp 2 for over 12 years with fantastic results. I also use a Boss TU-3 with absolutely no problems on the B-string. Even my Polytune clip-on works just fine on a B-string.
So, no more clip on tuners for me.