The only problem I've ever encountered with a break-barrel is pellets not being seated correctly and getting crushed when closing the barrel.
I have 2 under-lever Air Arms rifles and both are incredibly accurate, not sure I'd go back to a break barrel as I'd probably end up trying to blame any bad shots or fliers on the barrel not being properly aligned/closed.

Probably just personal preference though and maybe not that much difference in terms of accuracy in modern spring rifles.