Actually the app is not so bad on an iPad with JB, FullForce allows it to scale up to the whole screen. (Also looks pretty sharp with RetinaDisplay, but only expands to 2X, and the two extensions are mutually exclusive.) Plus Google Maps has StreetView, which is not available to the browser on any iDevice. On the other hand, maps.google.com now offers biking directions on both their Classic and Mobile optimized sites, something still lacking in the app. So neither solution is perfect yet.
Incidentally, managed to get maps.google.com to display in mobile and in classic with iCab by toggling the browser ID settings back and forth until they "took." Classic behaves kinda strange but Mobile is very stable, plus it takes advantage of virtual keyboard navigation when entering destinations. Also the site works fairly well with Cydia's Safari FullScreen, makes a convenient little web app. The extension is just a little flakey though and at times has trouble covering the hidden status and browser bars, d'oh!
Still can't get Maps to work in Atomic Web Browser.