Cons
-Kamen Rider in name only, virtually no links to the original concept and/or formula
This comment has always interested me, because in some ways the New Gen shows do sort of hold to the original formulas. Specifically, in the way that the origin of the Kamen Rider's power is somehow tied to the villain group.
-In Blade, the four Riders gain their powers through the use of the Undead. They require the Category Ace cards to transform, so in a way they require the power of the very enemies they are trying to defeat.
-In Ryuki, all of the Riders involved in the war (excluding the Alternatives? I can't remember) are granted their power by Kanzaki Shiro.
-For 555, the Rider belts were created by the SMART BRAIN corporation, but then fall into the hands of the heroes.
-Den-O gains his power from the Imagin ... again, the very same enemy the hero seeks to prevail against.
It may not seem like such a big deal to others, but it's one thing I've noticed. One aspect I would like to see return though is the "Quest of Vengeance" angle used in the older Kamen Rider shows.
I do agree with you on the under use of motorcycles. I was thinking about it a while ago and realized that Blade is the last Kamen Rider to have a heavy use of bikes. You almost always saw them riding or even sometimes using their bikes in battles. Strangely enough, I think even Hibiki has more motorcycle action that Kabuto and Den-O combined. Kuuga, Agito and even 555 had the characters using their motorcycles on a regular basis though.