Climbing at V
1.35+10 in the VC10K at Incirlik meant that we could make the correct level for the K-town transit corridor quite easily - whereas climbing at SOP best rate speed meant we couldn't. Not that many crews bothered - they were happy to ignore the Turkish limit...
At Abingdon (before it was squaddified), on RW 36 if you taxyed as close to the RW threshold as possible, then took off and climbed at best angle, you were reasonably well placed in the event of EFATO as the fields at the end of the RW ran east-west. If you climbed at best rate, you would be too low to position for a field - but at best angle you could either jink round to RW 08 or make a descending steep turn to position for a field.
There
are good reasons to climb at best angle, but to do so requires thought and quite careful handling.