I only choose to answer, because this is not a comment I'm afraid of...
Well, after looking over all of the other answers, I think you might miss a thing that pretty few people take in account when thinking about their "superior" battle-mechs.
Okay, mico villena noticed this kind of (the role), but I can't see anyone who cared about the question so what happens to my mecha when it got hit?
To keep the advantages of multi-pedal... traction, that thing should not get to heavy. And speaking of weight, it needs to be symmetrical and keep all the heavy stuff close to its center to avoid just tipping over when the walking ground is uneasy. Or sinking in. Tracks do spread weight pretty great... but I just need to remember my fat cat with its tiny feet walking over my belly... ouch.
So you can't use the same grade of armor you can plaster on a tank. These guys are flat and... well, they can tip over in heavy terrain too, but you have a pretty predictable surface thats exposed to attacks. Stack all your armor, hard- and softkill systems there and you get protection at a level no mech could reach.
So whats about the hitting stuff? Now compare your flat tank and a high walker. Let both of them get hit by a kinetic penetrator. Even if your walkers armor is (in theory) able to defect this, the sheer force will knock it off balance or even remove a leg.
Or a plain old artillery shell, that a tank won't notice as long as its not a direct hit with a bunker breaker concrete shell, might knock over your walker too thanks to its blast force. Maybe it can stand up again, maybe it break some components during its fall... But, yeah, a tank can get stuck in a shell bast hole, but that need bad circumstances or a driver daydreaming.
These mechs would need to... crouch to get their center of mass down, which means that they need to know that the attack is incoming. Event then it may take some time.
But to be honest... there is one thing they may excel in: avoid anti tank rockets. You see these things coming all the way? Just step aside just a split second before impact!
Your question... as long as you do not want to use them as a replacement for tanks, they will find a niche. And for some reason I opt for small bots that are used for urban combat. Just drop a few dozen of 'em at a building crawling with enemies. Bonus points for integrated C4 Explosives, all kind of sensors you can think of and silent weapons. Make them water-proof and they may enter that building from bottom up. Oh... nice toys. And the good old exosceletons of course. For impressions google terminator space marines
But really big ones? You may add a flag and a disco-light to them, that wouldn't make them more vulnerable at a modern battlefield. Their time will come, when you change kinetic and blast force as your damaging force for lasers and stuff that does not push.
EDIT: Oh, I forgot: what does have lags, can stumble...