I would imagine how useful the ability is would be dependent on the type of DM they have and whether those DMs tend to attack downed PCs?
If you have a DM who usually doesn't attack downed PCs, then having those death saves available allows the PC to have a longer survival time lying unconscious and not getting hit (while waiting for healing to eventually come). Spending those death saves for additional hit points though just means they will keep getting attacked while on their feet, and if/when they do get knocked out, they now are going to die quicker because they have no 3 death saves cushion.
Now if the DM does tend to attack downed PCs, then dying quickly is happening regardless... so at that point remaining on your feet by spending the saves allows the PC to get the hell out of Dodge and retreat. But that won't tend to result in what it sounds like you're going for, which is a 'last stand' kind of situation.
To me, death saves are more valuable to survival then the additional hit points, so it's not a trade I would tend to make. That's why I have fellow party members... to take up the mantle while I lay knocked out.
If you have a DM who usually doesn't attack downed PCs, then having those death saves available allows the PC to have a longer survival time lying unconscious and not getting hit (while waiting for healing to eventually come). Spending those death saves for additional hit points though just means they will keep getting attacked while on their feet, and if/when they do get knocked out, they now are going to die quicker because they have no 3 death saves cushion.
Now if the DM does tend to attack downed PCs, then dying quickly is happening regardless... so at that point remaining on your feet by spending the saves allows the PC to get the hell out of Dodge and retreat. But that won't tend to result in what it sounds like you're going for, which is a 'last stand' kind of situation.
To me, death saves are more valuable to survival then the additional hit points, so it's not a trade I would tend to make. That's why I have fellow party members... to take up the mantle while I lay knocked out.
