In the last ten years I have owned four titanium framed with three still in regular use and the forth was eventually part chopped for my current Enigma Effusion.
I do not have an Etape simply because I still have a nine year old Omega Axis which is currently being used for winter/wet weather chain gang use. This is an incredibly versatile bike as it was originally built for a touring holiday in the Canadian Rockies and the aim is to take it back (when I retire) for the full Canadian Coast 2 Coast ride.
In terms of performance my Axis does tend to be slightly more sluggish and require more effort on chain gangs than my Enigma Effusion, however for a touring frame it does still manage to keep up on a 20+ mph average ride with carbon road bikes.
Titanium frames do not creek however as they do appear to transmit and amplify sound better than any other material, whatever mechanical noise is generated else where titanium will tell you about it. For example the free wheel ratchet sound on a titanium bike is always louder and on the Axis I did have an annoying creek which came ironically from a titanium saddle rail, as this bike also had a titanium seat post, this was eventually corrected by swopping the saddle over from another bike.
The final reason I would go back to Enigma for a new frame is that they have the facilities for repairing frames in the unlikely event that you need this. Last year when I took my Himalayan mountain bike for new rack eyes, I noticed that Enigma was also undertaking a warrantee repair for another titanium manufacturer!