Balloon beds…
Pros:
*Ultra lightweight
*Compact
*Warm
*Well comfy (Moulds to your back)
Cons:
*Faff to inflate in wet or windy weather/small or crowded tent/the dark, etc
*Boring to have to inflate each night on longer trips
*You can’t risk using it as a campsite lounging around mat before tucking in for the night
*You can lose the odd balloon overnight if used outside your bivibag without a groundsheet, but….
*If you stuff it in your bivi bag then it rolls around with you and you can wake up in the night lying on your side on rough ground with the balloon bed still on your back.
HTH.