Answer to your question: if you want more damage, then YES IT IS WORTH IT! And: USE IT ALL THE TIME! And if you judge it, REFRESH IT BEFORE THE NEXT AUTOSWING! (so do not judge it just before one or you will get an autoswing without a proc chance)
As far as
couple pally's you've talked to about seal of command wrote:
arent impressed with it
Do not trust their opinion. Ever. Again.
Just to add a bit to the info already given: up until you get Crusader Strike as a retribution paladin you will not have any instant attacks nor will you probably have any haste ratings. The Seal of Command proc works with the "proc-per-minute"-system (look it up on www.wowwiki.com if you do not know what this is). Meaning that you will get on average 7 procs per minute, REGARDLESS of your weapon speed.
This means that a fast weapon with low min/max damage will get on average 7 procs per minute, doing 7 times 70% of its low min/max damage through Seal of Command. A slow weapon with high min/max damage will also get on average 7 procs per minute, doing 7 times 70% of its much higher min/max damage through Seal of Command. The conclusion of this is that you must use Seal of Command with an AS SLOW WEAPON AS POSSIBLE WITH AS HIGH MIN/MAX DAMAGE that you can find. Ergo: a two-hander.
Best example probably is the best 39 two hander for that level for paladins: The Pendulum of Doom.