Well, I only played her from levels 1-5, after which my DM allowed me to swap over to Sorceror when PH2 came out (she was a 3.5 sorceror converted into a 4e warlock, as that was the closest option at the time).
My biggest frustration was the MAD - it made it so I basically only had 1 at will, because it felt like I never hit with my con based one (my con was 4 points lower than my cha).
That, and my curse bonus never seemed useful - generally, I never got it until the end of an encounter (we had a serious lack of AOE in that group, so if I wanted the bonus for a cursed minion, I had to waste the actions cursing then killing the minion myself), and when I did, it didn't seem to make any difference (even with the feet that made it a +2 bonus).
Finally, I found the powers rather lack luster - they didn't really do very much that I felt was fun - no pushing, or interesting mechanics. Part of it was a problem with party synergy (my starlock, a str cleric, a sword/board fighter & dex/str rogue) - I had a great encounter power than gave a penalty to the target's will defence - problem was, the party had a grand total of 1 attack versus will, which was my own at-will power eldritch blast.
Now, part of the problem is that I'm not the right person to play a striker (I'm the kind of guy the warlord is written for) - and especially not the striker who realy doesn't seem to do much damage and does little else beside. And part of it was that I played through the levels with the fewest options, back when the only options were from the PH.
That said, now that I've played sorceror, I would never go back - while still a stiker, it is much more fun, with powers that push/slide, and other interesting mechanics like explode/jump/explode and run-through-enemies-to-damage-them. Now, I admit, that part of the fun is that I finally give the party some AOE, but a large part of it is me looking forward to using a particular power rather than, for yet another round, finding that there is NO power that I want to use and just eldritch blasting... again.
YMMV, and indeed I hope it does... I would LOVE to hear about how to play a starlock right and how you've fallen in love with the class. Already, you've dealt with one of my major iritations by having a con and cha that are much closer, though I'm worried about your ability to hit generally (my con was the same as yours, my cha was simply much higher). That said, I'm still of the opinion that the starlock is the worst build in the game.
