Non-Touring vs Touring - Mountain twisty road?

I understand there are differences in the suspension system between the Touring and Base model, mainly the McPherson struts in the rear, and of course larger wheel base and tires.
I found the difference is insignificant driving a rental Touring edition probably package 2 and purchasing a Base model package 6 with electronic stability and traction control. Both models seem to drive pleasantly and give the driver a very good feel of the road. I heard comparisons between the floating Cadillac (Base) and the BMW (Touring). Sometimes the mind can play tricks with you.
Both of these models are essentially the same car; Base and Touring owners can go to aftermarket companies to increase most of the features and Base model owners can pay about the price Toyota charged its buyers for Touring and transform the Base model to the Touring edition. Is the difference worth it? Is the difference one pays for a BMW really mean that its a better built and engineered car than a Lexus? or even a high end Toyota with similar features...yes? the marketing from BMW says it is worth it...the resale market dictates otherwise....especially as each car ages.
I am delighted that the Prius is the most thoughtfully engineered car I have ever driven.

 

We reviewed touring vs none and decide to go with touring...better wheels etc etc...beeen very pleased ....it is now almost 1 year old....no problems etc...

 

I've been on a waiting list in Las Vegas (1 month) on a Prius. I wanted package 6 (any color except Black) in Touring (gray interior). The dealer informed me that they average 1 in 10 allocations received is a Touring. I was notified today of a Silver Pine Mica -standard version with gray-which I'll probably commit to. My question is had planned to install the floor crossmember and strut tower upgrades once I receive my Prius. Wouldn't this upgrade the standard version to be almost comparable to the Touring.(I don't plan to pull 1 G on a slalom course!)

 

Touring handles 35 mph cross winds with gusts to 55 mph with just a little steering input. I drove a base model from the dealership in Alamogordo to the tunnel on the road to Cloudcroft with no problem with maintaining speed or twisty road (miles of upgrade). While the Touring doesn't handle like a Miata, it feels very controlled and confidence inspiring in the corners.

This is a great car.