Jetstreamtechrecords, maybe your concerns would be better addressed directly to Jetstream Executive/Express themselves as opposed to on an internet forum. You seem to have a rather anti JXT stance?
Surely it's time for JXT to realise they are missing out on a massive cash cow in a BLK-LON service. A twice daily BLK originating service into LTN would be a sure fire hit and extremely sustainable.
I think in the long term ABZ will work, the loads are all over the place at the moment but according to a friend they tend to be getting a very high number of on the day and night before bookings.