Electric heat is 100% efficient; power in = heat out (forced air electric heaters are slightly less than 100% because they use some energy to move the air instead of warming it) .
Even though electric is 100% efficient, it may not be as cost effective to run as a different energy source like natural gas or wood if your electricity rates are high. That may be what you heard.
As far as electric heat goes, you have 3 choices:
1. Electric radiant - typically used in large open spaces with occasional use or spot heating needs - heats objects directly, and heat is felt instantly. Air temperature can be kept lower while still maintaining comfort. Quiet, no moving parts.
2. Electric convection - baseboard or wall convectors. Electric elements warm the air, which rises naturally (no fan). Quiet, no moving parts, but slow distribution of heat due to lack of a fan.
3. Electric forced air - wall, ceiling, floor heaters. Electric elements warm air which is moved past and distributed by a fan. Quick heat distribution due to fan, but can be noisy.
Kevin
H-Mac