[4e] purchasing advice, and why warlords?

[Artanis]

I find the warlord being my favorite leader, they can be nasty even with sub optimal builds. Of course letting your rogue attack after you run up and flank an enemy is always nice (i love the warlord's at will)

Yeah. Commander's Strike is one of the few at-wills that can even pretend to keep up with Twin Strike.