I'm considering installing electric baseboard heat in a new addition to my house.
3 bedrooms 1 bath in the addition. Hydronic seem to be the best I've seen.
Any comments or suggestions would be appreciated.

How big is the addition?

24 feet by 24 feet

There is no difference between hydronic baseboard heat and standard baseboard heat. Electric heat is always 100% efficient.
Where the difference is between the baseboard is the hydronic heaters smooth out the cycle by allowing a slower release of heat. I would not spend the big bucks on some fancy heaters that save no energy.