I'll start by introducing you to the best bit of advice you'll ever hear about aviation: "If you want to make a million in aviation, start with 10"!
The only service that would be slightly more attractive than most is something Central Bristol to Central London - anything else and you just introduce extra journey time. Elstree for instance, if the traffic's bad (which it is in a morning) could easily be 90 minutes to get into London by car or an hour by train - so you've lost the key selling point you've got - time saving. For something like that to work you'd have to fill 7 seats on a King Air at at least £200 per seat. And that's only to cover the operational costs. When you then consider the most people you can carry is 8 or 9, you can see that you've still got your own overheads to pay - it's not a good money generating scheme!
The "would I use the service?" question isn't really a great one to use, you need to be far, far more cautious than that. Like I said before, if someone asks me if I'd use that service, yes, of course. But then when it came to the crunch, would I justify that expense to get me to somewhere close to where I want to go, but not exactly, then no, I wouldn't. I'd be surprised if the majority didn't think exactly the same.
With aviation everything's 110% effort - it's one of those businesses where if you don't put the effort in you'll miss the opportunities and you'll drop the ball - you only need two days of low loads to have written off your previous months' profits.
You don't come across too much as a head in the clouds type, but you do come across as someone with limited exposure to the pitfalls of aircraft operation! The moment you get into it you see how utterly expensive it is!
But you're right to ask people's advice before going and shelling out however many £XXX's on an aircraft!