Here's confirmation for you.
INV. YES 195. definitely, as the schedule calls for the crews to be mostly through their 195 conversion courses right now and Contract pilots are up there operating the 146. G-OINV I think as well.
IOM. No. definitely not. Absolutely totally not. Not this week anyway. The Summer schedule shows a lot of extra seats on the London routes and with this increased frequency. spreading the loads over more flights allows more seats to be made available and the Q400 means the cost of these is minimal, so a lot of low fares to stimulate demand. Put a 195 on and the extra costs, seating and no improvement in freqency just doesn't make sense.
When you think about the economics of the Q400 over the 146 we used to have, it's a no-brainer, the Q400 is a real winner in almost every regard. (except smooth landings and we're getting there too!)
GUR? dunno. Ask me one on sport.