I think it sort of depends on how you play - our games tend to have a few big fights rather than a bunch of little ones, so that 55 HP is sure to be used, and getting dropped to zero is not uncommon. I feel like when that kicks in, you'll be really glad to have it, whereas a bit of extra healing on short rests or from a potion...eh. Probably won't make much difference.
So… the number of big fights per day was brought up, but it seems we came to opposite conclusions

…
Recovery gives two effects that work just once per long rest. It has been argued (cogently, I would say) that the size of these two benefits is a bit bigger than what Fortitude gives. I think this is true, and it favors Recovery in the context of a single big fight.
Fortitude, on the other hand, provides two benefits that are "passive", or always on. It raises your max HP (though by less than what Recovery would provide in one shot), and it gives the (arguably minor) ribbon of increasing the efficacy of healing. It is argued that the improved healing is minor because in the heat of battle, you benefit more from spending one (or as few as possible) discrete action(s) to get as much HPs healed as possible, and in that context the Fortitude bonus is a small fraction of the total healing you get. Whereas during downtime you can use lesser forms of healing spread out over many actions, each of which dole out the little extra bonus. All in all, the passive Fortitude benefits are therefore lesser in the context of one big fight compared to the expendable Recovery benefits.
My point was, however, that if we make the assumption that at epic levels there is plenty of healing available during downtime (both with and without short rests), then the number of big fights per day affects the balance of power between the two boons.
Fortitude’s always on passive benefits not only increases healing efficiency such that the downtime has a greater likelihood of bringing the character back to full health, but importantly, the raised ceiling of max HP can therefore be replenished multiple times per day. This means you can get into multiple big fights with those extra HPs in the tank (assuming you had at least a little bit of downtime between them, though not even necessarily as much as a short rest).