I would agree that when FlyBE are operating to schedule they provide a fine service, however, since they became a "low cost" operator the service to the Channel Islands has deterioated dramatically.
In the past when weather or technical problems occured the flights were just knocked back or alternative aircraft brought in. SLF can accept this, they may not be happy but at least they can see what is happening.
Unfortunately, the policy now appears to be cancel and rebook and over busy periods you may find that the next available flight is two or three days away, make such you are first to the ticket desk, no preference is given to the fare you have paid.
The issues raised by FB are common and if your are flying to the Islands you will more frequently obtain more factual information from the handling agent in the Islands, this certainly applies when flying from LGW, BHX and SOU. I have been stuck in all three locations recently and the delays have been blamed on CI weather, after speaking to Servisair, I find out that the BHX aircraft is still in GLA with a technical fault (Q400), eventually rebooked for the next day and travelled on a 146. In LGW the GCI aircraft had been required to do a LGW-JER-LGW due to a technical problem in JER, arrived three hours late and in SOU a cabin crew member had suffered from the heat in the cabin of the Dash 8-300 and been unable to continue, flight was cancelled. Subsequently reinstated only to find SOU runway was closed for a charity run and we were coached to BOH.
If time is of the essence, then don't travel with FlyBE on the BHX channel Island route, the reliability of the Q400 is a major issue.