Key to longhaul from BRS on the Dreamliner is the Yield per flight. The flights will I think be payload restricted and some will be lost to weather but because of the high demand the yield will be high per flight. Therefore even after diversion and restriction the routes will be profitable. LBA too has a short runway and is even more elevated and across the prevailing wind. It is not the proximity to MAN of LBA which will rule out Dreamliner flights from LBA but the location within Yorkshire [allied to accessibility and functionality] which more than halves the demand. Low demand equals poor yield. Incidentally, as we speak BRS is now twice as many passengers (rolling) as LBA and pulling away. Bristol, although far from ideal in terms of airfield characteristics controls the catchment. If it did have a runway extension, a la BHX, it would grow even more quickly like BHX is doing now.