Andy, LBA is 2250m long enough. Bristol has a CO 757 flight to New York direct from it's 2011m runway. LBA has had direct flights to Toronto in the past and that includes a 747 on the day the extension opened. Weather and local terrain make direct to East coast not always possible but I believe a 300m starter extension has been discussed to counter this.
DSA may become Yorkshires No1 but I would doubt it if the LBA bosses wake up and invest in the place as it's far better positioned than DSA for conurbations and is more central within Yorkshire. Lets not forget Leeds is rapidly becoming a very important city for commerce and has an Airport on it's doorstep. Whist DSA has far better transport links LBA could and should do more to resolve its's weaknesses here.
Time will tell but I wish all 3 Airports well. HUY will have it's part to play too.