the 123 works extremely well -once you understand its true advantages and limits
I use both LiPo and 123 cells for power -
If the plane is designed around the 123 - it is prefferred setup --to me .
until you hit about a 3 lb (1.5 kilo )all up weight the LiPos are better .
I am not talking about competition intended models - just nice, fun to fly ,high performance types.