I always carry a dinghy transatlantic. Required kit by Transport Canada (at least) for starters. If you get ramp checked in Iqaluit (unlikely admittedly) where are you going to find one there ?
Bloody nuisance too; heavy, bulky and how do you get it back again across the Atlantic by scheduled with CO2 cartridges included ? Answer : you cannot, not legally anyway and the potential financial penalties if caught doing this are set at bankruptcy level IIRC.
When it comes to deployment will your raft work as advertised ? Indeed, will your fingers work at currently prevailing temperatures out there (I crossed last week) ? Having worked, will your raft be ripped from your grasp by a boisterous 40kt breeze and disappear inconveniently over the horizon ? Probably.
Yes, there are those that fly without rafts and some even fly without immersion suits too. But then if you have no suit you won't need a raft. And a suit not worn while flying oceanic is about as good as having no suit at all.
But I carry both and just hope that my crossings will be really boring from an operational point of view. So far, so boring ...
SI