Robotic systems in the HU2 setting emulate human attributes; increases in these attributes will cost money. One of the first problems I found is that HU2 avoids the concept of a robotic PP attribute. The analogies may not be exact, but I think that all humanoid robots have an effective PP comparable to those of a human. This is especially important for unpiloted robots; what separates a clumsy prototype from an advanced combat model? There needs to be an attribute reflecting the same things that PP reflects for humanoids. Other attributes may be appropriate as well, reflecting the other aspects of a humanoid body.
My chief complaint is more of an overall flaw in the system: Players are rarely forced to sacrifice advancement in one attribute if they wish to increase another. A robotic player character using the standard HU2 rules could easily afford the maximum upgrades of both speed and strength available for their robot. I don't think that it's appropriate for characters to have access to the pinnacle of robotic engineering with only their start-up funding. Robotic characters don't have much room for development and this just exacerbates the problem. As a robotic character builds experience they will likely build up cash reserves and earn favors from powerful NPCs. Their systems could then be improved and replaced over time, reflecting the advancement other characters receive as their experience levels increase.
I also don't like the limits placed on robotic PS. The limit for human-sized robots (PS of 30) is really low compared to the powerhouse SPBs one can create, and the relation of height to possible strength isn't very satisfactory. Finally, the cost of an increase in PS shouldn't be directly proportional to the amount of increase it corresponds to. As PS gets higher it should be become more difficult (and expensive) to further increase the attribute.
The upper limit placed on robotic speed attributes is silly. I can accept that humanoid robots might be able to run at a couple hundred miles an hour, maximum, but it doesn't seem likely. The fastest ground vehicles in the world rarely exceed a few hundred mph, and the fastest animals can only approach one hundred mph for very brief sprints. Robots are limited by the same problems that limit other speeding objects; some of the factors preventing these incredible speeds are:
The above arguments are, I believe, sufficient to prevent nearly any robot from attaining running speeds greater than about 100 mph. Of course, the Palladium system is set in a fictional world where technological advancements far exceed our own. The most powerful argument, regardless of tech-level, against robots with incredible speed attributes is that no one would spend the time required to develop the technology. Why does a robot need to run at 750 mph?
Finally, on a gameplay note, I don't think that it's appropriate for a player character to easily afford the maximum speed attribute attainable by standard technology. The speed increases in HU2 are far too inexpensive, considering the mechanical difficulties involved. Robotic characters don't have much room for growth in the current system; by increasing the cost of the peak performance system to 10 or 20 times the cost of the basic unmodified system the character is quickly limited by initial funds. As the character earns upgrades and/or money for his services he can afford more expensive systems. This vast increase in cost will serve game balance, and character development, as well as improve the adherence of the HU world to reality.
Also see my corrections to the Super Ability Extraordinary Speed....