It appears my portable 396XT "locks" in better/faster than the base 996XT.
Today I was comparing, both scanners on HOLD on East Tower, East Tac 3 on a fire call, the portable 396XT with a stubby antenna and the 996XT with a much larger antenna (both reading full signal, but it doesnt matter because they get full signal even without any antenna plugged in on the east tower), and the 396XT was locking into the transmissions almost instantly, while the 996XT was flickering between LNK/DAT, before sometimes locking into P25 mode 3-5 seconds later, or not at all on a given transmission. doesnt matter if it was dispatch or the firemen on scene.
It's the exact same programming file uploaded to both scanners via Freescan.
I have firmware 396XT is 1.10.00, and on the 996XT 1.07.03