That's all assuming that battery technology has reached its peak in 2014, and that we will never come up with a superior form of storing energy. Which is ludicrous.

I agree that bodysuits should be bulky, and that they should have weaknesses alongside any strengths they have. At the same time, I don't think we should argue this down to the point that all we have is a 2014 World War simulator. If you are going to RP something in the future, you kind of have to loosen the rules and tech a little bit elsewise you pretty much just rubber band back to the modern day. 

I suppose at the end of the day the thing we should be instilling is a tendency toward bending the rules in order to make something cool and interesting in the context of the plot rather than something overpowered and masturbatory as the original suit idea was. We don't want to swing so far to the extremes that we are just playing idea whack-a-mole and only allowing the things that we know to happen. 

Suits should have weaknesses that counteract their strengths. If they are well armored and equipped with a lot of implements, then they should be slow. Perhaps soldiers who operate them are required to have certain sorts of cybernetic surgeries that take something away from them psychologically or physiologically. And of course, they shouldn't be invisible.