Entirely up to the player. Hard toe boots (supposedly) slow you down a bit, but personally I got tired of losing one or two toenails every season. But I know some prop forwards and locks who feel differently. A back choosing to wear hard toes would be unusually, but if they prefer to do so, more power to them. Many of them will sometimes forgo rugby boots for the soccer boots with the molded plastic blades which are (again) supposed to be faster on a hard dry pitch. Bottom line -- whatever works best for you.
It seriously doesn't matter what sort of boots you wear. I've always played in the back and as like you i used to wear a pair of T90s or Mercs. As a flanker or a back its better to have lighter boots, because pace is one of the main parts of the game. Its rare your boots will be stood on, plus were rugby players it doesnt matter if theres a little pain now and again from someone standing on you :P If you are getting the FG's its probably best if you buy some HG boots as well, for when the winter comes and the ground hardens up. You've picked a good pair of boots for your position though mate.
as a prop i never used hard toed boots.
Most backs wouldn't use hard toes boots. Most tight forwards would. Asa flanker/back it would be entirely your own choice but I would think soft toed would be more suited.
i play prop, and second row and have never worn a pair of hard toe boots
