was cheaper than one way on a BA flight per seat.
I doubt that.
You would need to factor in depreciation, maintenance and other operating costs to make a valid comparison.
However, we fly for the fun and utility, if we flew for the cost savings then I guess we wouldn't!
Its a very good aircraft. My own view is its not quite the same package as the top end US SEP hardware, but is close, and assuming the engine problems have been resolved represents good value for money.
Cirrus, Mooney, TB20s to mention a few without doubt offer a quicker more capable package - albeit at a price and without doubt with a much more costly fuel burn. The DA42 compares with these far more favorably but leaving aside the twin versus single debate its still probably not quite a good.
I would love to see a DA40 with the performance of a Cirrus.