For wait times it will most likely be Shorter with Mosaic - it would be 8-12 weeks not 8-12 months(purely guessing on this I haven't checked with Firefly lately) unless you want to pay Firefly a Premium for an early spot if they still do that.
That being said I'm just in the process of Ordering a Mosaic but i love the Firefly Drop-outs - Works of art.
I got my firefly in way under that time. you don't need to wait 8-12 months. Got mine in under 3. i paid the fee. I love the drop-outs and the anodized treatment. but if i was simply looking for a solid titanium bike and the aesthetics were not the top priority I'd probably go Seven Cycles.
+1 for Seven Cycles. A crew of ex Merlin folks who really led the Ti evolution.
I have an Axiom SL, and just I built up a 622 SLX (carbon tubes with ti lugs and chainstays). Both bikes are absolutely exactly what I was looking for. Custom process was comprehensive without excessive wait times (about 8 weeks in both cases). Also had a Mudhoney SL, but sold it to partially fund the 622. I definitely would take a look at Seven before making a decision.
_________________The Stable http://www.flickr.com/photos/121194764@N07/albums
622 SLX | Axiom SL | Mudhoney SL (retired) | S Works Crux | Fondriest Carbon Magister | Fat CAAD 1