Ok. Here's the take I get on the martial adept classes vs. the traditional fighting classes and why I disagree with the idea that the Martial Adept classes are more powerful. This is not to say that they are weaker, just not more powerful. Here is how feat users (like a fighter) compare against the new "martial adept" classes.
Feats vs. Maneuvers
1. The Action Log-Jam: Feats don't typically take actions to use. They are usually either always on or work as part of an action that is already being taken (such as a move or an attack). Maneuvers (particularly strikes) take an action to use like spells (usually full-round or standard). Plenty of maneuvers take swift or immediate actions, but they still require an action and can result in action "log-jams" which prevent multiple maneuvers being used in the same round. Martial adepts can execute at best 2 maneuvers in a round. (mainly a full-round or standard action + a swift or immediate action). Maneuvers also are spent once used until you execute the prescribed action to re-set them. You cannot simply use them over and over again even if the situation would warrant it. At best you can re-use a maneuver every other round (warblade). Classes like the Crusader can't even use them that often.
Stances don't take an action if you are already in the stance but the ability the stance allows you to use may in and of itself take an action. It also takes a swift action to change a stance (which may result in a limitation on your ability to execute a maneuver).
Feats generally do not take time to activate. A few do but most don't. They activate as part of an attack action of some sort not as a separate standard action, consequently you can use as many as apply in the situation.
2. Stacking: Assuming you chose them properly, feats stack with nearly everything unless something states otherwide. Martial Maneuvers don't stack very often due to short durations (usually for the round at most) and due to the limited number of actions available to activate them.
Note also as the Book of Nine Swords states, strike maneuvers do NOT stack with special attacks (including feats) or with extra attacks such as by way of haste. Unfortunately the book is very vague on these terms. Only two examples are given of "special attacks" (Sunder and Bull Rush) but it is pretty clear that combat feats like Power Attack qualify and thus cannot be used with a strike maneuver. Basically if you can say, "I execute a <insert name of ability or feat>," it is probably a special attack and thus cannot be used with a strike. Also per the Book of Nine Swords, extra dice from maneuvers don't multiply on critical hits.
3. Feat Limitations: Note also that many feats only work when you take an attack action of some sort. Using a martial maneuver can be a Standard, Full Round, Immediate or Swift Action, but they are rarely if ever an attack action. Note some of them allow you to take an attack as part of the maneuver but that is NOT an actual attack action. Consequently, many of the fighter-type combat feats are near useless for a martial adept. The adept can take the feats and use them instead of a maneuver but he can't use them WITH a maneuver to improve the effect.
4. Dead-Weight abilities: This is a little hard to explain but I will try. Martial Maneuvers have levels like spells. They also have pre-requisites like feats. This results in the odd quandry where you sometimes need to stack lower level maneuvers (of which you only know a limited number) to satisfy the prerequisite for a higher level one that is sometimes merely an improved version of the low-level one.
Yes the rules do allow for maneuvers to be swapped for new ones, yet due to the limited swapping and prerequisite rules it may not be possible to get rid of all the old maneuvers that have been superseeded by new ones. Couple this with the fact you cannot ready all of your maneuvers for use at once, this means that older low-level maneuvers will tend become "dead weight" unless they have special properties that are useful for a particular situation AND the adept knows in advance that that property will be required.
Stances aren't as much of a dead-weight. While at high levels you can get as many as 7 stances (one active at a time) they are always ready and you can switch them as a mere swift action. (Note: Warblades can have 2 stances active at high level).
While on the surface this may seem the same as spells, that is not the case at least for spontaneous casters for whom their entire repertoire is ready at all times. They can choose to use use a low or high level spell at any time if the situation warrants.
Prepared casters may not have all of their repertoire ready at all times but their long-term spell selection is not encumbered by dead-weight. If the spell is no longer useful, they won't memorize it. The only real loss they suffer is the initial cost/time outlay and space in the spellbook.
Feat-users can have a dead-weight feat problem, but that usually results from poor planning. Most feat-users choose their feats BECAUSE they work together or because they are prerequisites. Even if you only took the feat as a prerequisite, nothing stops you from using itIt just may not be helpful at the time. Dodge may seem like a dead weight feat to get to spring attack, but nothing is stopping you from using the dodge bonus anyway so long as the situation warrants. It doesn't simply sit there and take up space.
5. Summary.
Martial Adept pros: Plenty of powerful abilities at maximum current level. Abilities can also be versatile and have a nice "cool" factor to them.
Martial Adept cons: Difficult to execute more than one powerful ability per round. Maneuvers have little stackability. You tend to attack with a single powerful attack instead of several lower-powered attacks.
Feat user pros: No action log-jam. Feat combos combined with multiple attacks can be a winner.
Feat user cons: Without multiple attacks and feat combos it is hard to do anything potent. Lone unrelated feats make for a weak fighter.
Tzarevitch