I can't speak for the Felt...and I will be in the market for a touring bike soon myself. Looking at 105 endurance carbon frames it looks like the following:

Z4 $2070:
http://2013.feltracing.com/USA/2013/...Series/Z4.aspx

Roubaix Elite 105 $2600:
http://www.specialized.com/us/en/bik...sl4-elite-105-

-or- Tiagra set:

Felt Z5 $1759:
http://2013.feltracing.com/USA/2013/...Series/Z5.aspx

Roubaix Sport 105 $2100:
http://www.specialized.com/us/en/bik...sl4-sport-105-

I'll probably ride both (or whatever is around spring 2015)...but the I feel the Roubaix comes better equipped in both situations ($340-530 better? possibly). The Z5 has some pretty questionable stuff on it...the saddle, wheels, cassette, chain, crank and brakes don't look so hot and those items alone cost WAY more than $400 to replace. The sport 105 is still a Tiagra/105 mix with a good saddle.

Either way...I'd have to ride both and see which feels better. I can say though that for my $$, I feel the Roubaix Sport 105 is well worth the extra $340 over the Z5. Betwen the Z4 and Elite? I'd have to see the in person to make that decision.