I have not tested those tables because:
The thing with wearing heavy armor is that you really do not care as much for defense anymore. Especially plate armor, used with good padding, will protect you from most blows. The only way to pry a knight out of his armor is by exploiting a weak point in his armor, or using a can opener: a very heavy one.
The low to-hit values on plate, heavy chain and heavy rigid leather simply mean that the wearer is more easily hit, because he doesn't care for those blows.
I do agree however that the quickness penalties are debilitating. I'd rather see them reduced by 5 for SL and RL by 10 for CH and 10-15 for Plate. The old table for Armor type penalties is based on a Mark Twain story, presumably, Yankee in king Athur's court, where full plated knights are hoisted on their horse. However re-enactors in faithfully reproduced armor have demonstrated the great freedom they still have, even when wearing 70 pounds of armor. I have worn full hauberks myself, but after taking in account the added weight I didn't really notice wearing the 60 pounds of mail. I was a little slower and slightly more clumsy, but nowhere near the debilitating penalties assigned to an untrained user by the RM system.
This is one of the nicest vids I found on medieval battles in Russia...TODAY! They are wearing fairly authentic russian armor (mostly mail) and those guys really try to inflict some damage. The only re-enactment trade-off I see are very heavy padded gloves those guys all use and PROBABLY (but I speak no Russian) their weapons are blunted. Check that split shield in the middle of the vid: that is how hard they try! and I see no one get injured. Probably some bruising, but no major injuries.
http://www.youtube.com/watch?v=8xAbuL0_nPs&feature=relatedFor people interested in more vids: look at the side bars and follow the links around.
Enjoy!