Yes living just north of Belfast I tend to forget it's 3 hours from the north west and 4 from parts of Donegal. All the more reason to have a strong BFS
Completely different story if you live in Newry.... but argument applies the other way too since Belfast is just as accessible as Dublin from a lot of areas south of the border.
For Dubai I would prefer to connect - plenty of options since EK serve 6 UK airports (sadly not Belfast - yet?). If just connecting in the middle east then there are even more options, I've used both Dubai and Doha (twice) for connections to Asia.
The US is slightly different since I hate flying in the 'wrong' direction, but even then I'd prefer to connect so long as the price is right, I just hate that 2 hour drive after a long flight!
Not sure what most businesses do but our company only book us travel ex BFS or BHD.