New bike fever

Have started doing rides is the 20-35 mile range and enjoying them. I currently ride a Trek 7.6 WSD and have not had any significant issues, even ramping up from very little riding to 30 miles. But, of course!, I see these nice road bikes passing me and get the fever. So I have started to look. Would like to continue to do longer rides and maybe one day do a century. Also, thinking about a sprint tri at some point. 53 years young, 5'5 1/2" with 30-31 inseam. I rode Scott Contessa, Trek Madone and an '10 Cannondale Synapse (I think-red and white). The '11 Cannondales are not out yet and that bike shop does not have Specialized and I plan to ride those as well. Got on a Madone and looks like a 52 would be closest, though my seat height is still at or slightly below handlebar height which was suprising. On the Contessa seat was well above. Shop there really likes the Madone (lots of the guys ride them). Suggested going up to the 6 frame if I could swing it as they say the difference is significant. Could then maybe save on components by going to SRAM and maybe the wheel set on the 5...

So, lots there. And I am just starting to test the waters and will be riding lots of bikes over the next few months. Questions:

Any thoughts on SRAM vs Shimano-- Have heard shifting can be less smooth on SRAM (Rival AND Force or just Rival?)

Any thoughts on the Madone geometry/fit as I described it? Is moving up to the 6 frame worth the investment?

Other bikes to put on my list? And any other thoughts on this process?

Thanks a lot!

Welcome! Good luck with the search. I tried a Ruby Elite Apex, 2010 and 2011 Madone 4.5 and then found a steel Independent Fabrication bike with Campy Chorus groupset. I want the IF bike very badly and it is 3200.00. I rode her for 20min and fell in love. But I am not certain she is $3200.00 better than my 5 year old slightly used Trek 1000wsd that I've been fixing up to be a decent bike.

Most people will tell you to choose what feels right. I honestly couldn't tell you which of the three feels right but I loved the steel bike the best.

It's very hard to know when you are a relative newbie. My riding distance is similar but possibly slower LOL.

Good luck finding the perfect bike. The one thing I LOVE about Madone series 5 and up is that they are hand built in Wisconsin just 45min away from my home. Love buying a made-in-US bike over a taiwan bike y/k?

Giant? The Avails have long top tubes compared to others (as I've been finding). You're a hair shorter than me with a comparable inseam, so it might not fit, but try it out all the same.
(This is just my experience. I'm on the short end of what Giant recommends for a medium frame. Since you'll be on the taller side of a small, you might not have a problem.)