Ive sat in a few different bucket seats in defenders. Yes they are comfy once your in them but therein lies the rub, if you'll pardon the pun...
They are a pita to get in and out of. Unless you spend money and get defender-specific ones that have low base sides.
You pays yer money etc... Personally i wouldnt bother unless you have the budget to get defender-specific ones OR you are lucky enough to find some from a car that have low base sides.