We got rid of the lid groove on the newest version. It proved to be unnecessary since the lid clips are used to center the lid. The groove was causing fit problems with odd-sized metric acrylic tube, and did nothing to center the lid or help performance in any way.
BrklynArch, re: wiper, the short wiper is ok if that portion of the neck doesn't normally get too dirty. Usually the upper part is the worst. I'm happy to switch out the blade for you if you need it though. Just send email with your order info.
Justin