(Speaking from the Imperial PoV since poster said Black Talon)
I COMPLETELY agree with the OP, Black Talon is an extremely well-done Flashpoint. I couldn't wait until I leveled to get to the next one. Then lo and behold, Hammer Station! YES! Shush up droid, let me go and start my next wonderful Flashpoint.
Speak to Darth Malgus? Awesome, i get to talk to this epic Sith.
Spoiler blocked proceedings of Hammer Station for Just in Case, I guess...
It was like, what happened to all of those lovely decisions in Black Talon, the buildup to getting to the General? Feeling like you were something aside from some fresh new meat?
And it seems grudgingly so through Hammer, up until Cademimu. The Call to Arms questline which starts with Boarding Party I can't speak for, since I've yet to find players to do it in my server. However, Call to Arms looks like it'll finally have some real story behind it again, but that's a pretty long stretch from level 10 (Black Talon) til 33 (Call to Arms); with roughly four Flashpoints (Hammer Station, that one with the Sith, Mandalorian Raiders, Cademimu) that are just vastly uninteresting in comparison. Sure, I've no problem with killing things, but don't butter me up with this lovely first Flashpoint, only to have four disappointments.