Yes, unfortunately, your experience is the same as mine. I have 2 Unications. One is Site 1. The other is Site 17. Sometimes traffic is on only one site and sometimes it's on both. You never know which and when. So two units.
Did this submission change from what it was? If it did, I don't think this new info is correct. Thank you for putting in both. I will do some testing with both the new and original. FYI, as of now I hear them on the original.
I would get an SDS100 or 200. Then based on what you can listen to, you may want to consider a Unication G4/5 series down the road (mostly) for P25 comms.
Pretty much your only scanner choice is the Uniden SDS100/200 for simulcast. Location and elevation will dictate how far you can receive. For P25 NJICS for instance, you will most surely get Site 17 (Passaic County) since you are in the simulcast. And you may get Site 1 (Essex County) but no way...