I test rode some of the same bikes you tried and I ended up going with the Ruby Elite. I'm also 45.

Questions to asks in reference to bike fit.

1) Height wise - you need a frame that fits your height. If you're not sure that is an important question

2) slight bend to the knees when sitting on the saddle - ask how much is good for your height

3) Handle bar reach - how much lean and bend to the elbows should you have.

4) Or, do you want a more upright position - you can have them set the bars to your specifications. What feels right for you.

Questions will come to you as you try the bike and so don't worry and over think it.

Good Luck