Just realized it's asking for feedback too...
There's one thing I've always disliked about the new terrans... and that is the Marauders.
The Marauders always seem very OP. They have high armor, can be built by barracks (so 1-1.5 tier), high explosive dmg, slows enemies down, has the same speed as marines, AND can be stim'd. Other than the fact that it can't attack air units, it doesn't seem to have any other weaknesses. It's fast, and focus-fire will eradicate "big" units designed to cut swarms of enemies, such as a pack of marauders, i.e. the colossus. I feel that, other than resource cost, there are no detriment to getting marauders, and that it has become the bread and butter unit of terran (like Hydras were back in SC1)
An idea would be to make them move slower. Since they really pack a lot of armor, it works aesthetically. And, in gaming theory, their slowness makes them less of an assault unit, and make it harder for them to gather and focus fire on larger enemies as long as the opponent's smart enough to move the dmg'd units away. With stim, this effect is basically gone too, so technically it acts like the zealot speed in SC1 just to tone down the sheer strength of this unit in the early games.
Not to mention that the terran has the add-on that allows them to build infantry (especially marauders) in alarming speeds.
Looking at other races, they do NOT have any early tiered units that can face the marauders. Roaches are desimated by focus fire, and zealots REQUIRE the upgrade "Charge" to even get CLOSE to the marauders (exageration, but not really).
So, In Summary, The sheer strength of marauders, plus it being a low tier'd unit, and terran's ability to double their productions make them an OP unit that other races simply could not outmatch without building other specific units to counter (such as air units). Suggestion would be to make their speed slower, giving them a handicap while assaulting other's base. Their speed can be redeemed with the stim upgrade.
NOTE: I'm up to discuss about this, because it's only my opinion, and I'd love to hear other people talk about this (maybe in another thread if it gets out of hand)
None.