I'd vote they are going UHF P25 for sure. Vernon, South Windsor, Enfield, etc. are already there. I'm sure East Hartford will be right behind them too. Only 800MHZ P25 departments local is Glastonbury. SW WAS 800MHZ, but switched to UHF.
Marcus Communications has had two major trunked systems for years... Both LTR, one standard which can be entered and monitored and the other Passport which cannot be easily monitored... only by entering the freqs conventionally, which means the channels have to be scanned manually since the scanner will stop on each channel on not scan.