The new robot mode is the spit of the originaal for the most part, with the same drum head and surpisingly minimal alt mode features - aside from the wheels on the arms and legs, the cab windows on the side and the drum on the back there's little clue as to the alternate mode.
I'm always divided on this as a matter of style; you don't want a robot that's a vehicle stuck on its' end with limbs jutting out, nor a shell that peels away like basically every Transformer made between 1997 and 2000. At the same time it's quite an engineering feat to hide so many parts away so naturally, even if does leave Mixer Robo looking just a little bland. The proportions aren't fantastic either, probably coming off worse than the original with the head being a fraction oversized and the arms a fraction too weedy.
The clean robot mode does give Mixer Robo a really good range of movement but the problem is that the head clips in and has no neck movement - so, like Bike Robo he can't pull many of the poses the limbs and exquisite balance are capable of off without looking a bit weird, while he's also the first in the series to be missing a waist joint.. A minor saving grace is that the face can turn as part of the transformation, though you can only get a few degrees before this looks a bit odd too. Oh, and to round off the strangeness he has a pair of combat knives as weapons. Despite never even looking at a knife in the cartoons. And they're not some weird robot-y bits that look like knives, these things could come off a G.I.Joe and might even have done so. Like some of the previous weird choices of weaponry like Bike Robo's axe it doesn't do any harm, it's just a bit bizarre.
Transforming Mixer Robo is a really fun experience as it follows the original's fantastic sequence with a few bells and whistles added. It's all low on frustration and full of neat work, the rotating face being a nice touch as are the wheels and drum. It takes a few tries to work out the best order for getting the cab jst right but that's more a strive for perfectionism than a problem.
Mixer Robo's cement mixer truck alternate mode is still every bit as odd as the original, which if follows closely. While the actual layout is good, only the obvious destination of the robot's arms being a problem, it's a very strange colour scheme. Red and silver in patches largely dictated by the robot mode layout (red arms and legs) makes for a strange patchwork and it looks more like a prototype scheme left in place rather than an actual construction vehicle. The turning drum is appreciated, however, and if you're after strange additional features his knives can clip on behind the cab looking sort-of like smokestacks but not actually like smokestacks.
Overall Mixer Robo's fault is that he's a cracking homage to the original figure, in that he's an exquisitely well-engineered way of turning a mediocre robot into a mediocre vehicle. Personally I find the mechanics more than enough to make the update worthwhile; that and the fanatical completism. For anyone else the sad truth is that there are probably enough bugbears to make this one a pass unless you're actively collecting and reminding yourself that most of the problems were build into the basic design.