Sure, at the end of the day it's only "my opinion", but I do truly believe that the '89 Batmobile (and 60s Batmobile) are subjectively better looking vehicles than the Tumbler (and anyone that says otherwise is simply being coy). It's just one of those things. The Gary Oldman Gordon is clearly better than the Pat Hingle Gordon, just like the '89 Batmobile is clearly better than the Tumbler. Nathan Crowley, the designer of most of the Nolan Bat-World, claims a Lamborghini and Humvee were inspirations for the Tumbler, and I believe him. The finished product however, does not resemble either. Look at a Lambo, it's elegant, sleek and beautiful. The Tumbler is neither. Look at a Humvee, it's a flat, tough truck. What element did the Tumbler take from it? Nothing but maybe it's panels (which the Tumbler clearly over does with it's front, sides, and flaps. Crowley himself referred to the combination and outcome itself as "ugly" in the making of featurette, it's own designer. I don't think I'm far off with my assessments.
I never got the tank comments (other than, again, forced Goyer-Nolan exposition where the cops claim it appeared to be "a tank"). I've seen all the Bat-Vehicles in person, 60s to 2008, and the Tumbler is one of the smallest. The '89 vehicle is much larger and stronger looking with it's length and sturdy design alone. A tank has tracks, where are the Tumbler's tracks? A tank has a haul, skirt plating, the familiar cupola/turret rig. Where are those things on the Tumbler? There's not a single thing in "real life", that resembles the Tumbler, not even in the military. The only way we come to that conclusion in the film is from the writers and it's original beige camo. In reality, the only Bat-car that is of our "grounded world" is that classic Lincoln Futura that was used for the 60s show. Everything else from Burton to Nolan was made up by designers for fictional films.
People may like the Tumbler, sure, and that's their perogative, but I do think it is in reason to call it a paneled monstrosity that resembles a small, compact beetle thing that is inherently ugly and devoid of style. It's the same deal with those that call the Schumacher vehicles garish and gaudy, sure, people may like them, but they ARE garish and gaudy.