I used to use it when it was Notator on the Atari, and before that i was using C64 with midi devices, so please don't think i'm a newcomer to this who's overly excited that i can suddenly afford to buy 'pro' software!
I certainly aren't a Logic cheerleader, it's cost me so much money in the past couple of years swapping between DAW's as Logic was being a complete pain - However, X seem's pretty stable to me, and most importantly i'm enjoying being a Logic user once again.
The only comparable product was Reaper, but again, i ran into problems with that - Right now, it would be my alternative however.
I use Logic for occasional professional use (Video and Game soundtracks), but not to compose my own music - that's purely a hobby that i enjoy.
The thing is, Logic X hasn't taken anything away from what you currently have, is running solid even on a .0 revision, and will offer significantly more as the upgrades come through - i'm not trying to argue, i'm just trying to shed some light on the positives.
It's easy to get caught up on technicalities when the true test is how well things come together, just a change of clothes can make you feel a better, more confident person. I think the same is true of aging software lol.
If you were to jump ship, which DAW would you move to?