I don't like the combo counter at all; from a design standpoint it makes no sense to me. Combo counters are usually in games to reward a well timed series of varied, chained attacks. Warframe's melee doesn't have timed attacks, and instead of rewarding variety, it rewards doing the same thing over and over until the end of the mission. You could argue that Warframe's combo counter is the exact antithesis of what a combo counter usually stands for.
I don't know all of what they have planned with melee 3.0, but I feel like it won't be enough. It needs a complete overhaul; having such clunky melee combat in a game where I roleplay a robot ninja is just a sin, especially considering how they absolutely nailed movement. Quick, responsive attacks that flow seamlessly together with both my movement and the rest of my arsenal... I can dream, right?
They're half-assing it as usual.
Spinning is getting gutted (including Maiming Strike and the rivens that do the same thing). Reach mods are getting gutted (with a buff to base range which will inevitably not be enough to compensate). The combo counter is getting gutted--it now only applies to a single heavy attack and is reset after. They're presumably also killing Blood Rush and Weeping Wounds. This is being "compensated" for by a buff to base damage that we all know won't be sufficient.
They're also removing channeling for the time being because they don't know how to make it useful for general use, which incidentally means that Life Strike is dead until that's resolved.
So essentially Melee 3.0 is removing every useful application of melee and leaving us with a situation where the tip-top of melee meta is back to the handful of half-decent stances. Expect to see the return of Broken Bull heavy blades and Volt speed-spam.
See, here's the thing: melee is, in abstract, far less viable than gunplay or ability spam. In low level content it means having to run up to every single enemy that you can one-shot. In high level content it means having to get close to things that can insta-down you, constantly. The melee meta around slide-spinning with memeing strike in conjunction with using Blood Rush + Berserker oriented around
mobility more than anything else. You can still expect to see slide-spinning after Melee 3.0 if they don't completely destroy it for that simple reason: most melee in Warframe, a game built around an extreme degree of player mobility, is highly immobile. In high level content, standing still means dying. Most melee forces you to stand still. Allowing dodge-cancels out of attack animations won't resolve that.
The other two current melee metas are the handful of good stances (which all have a universal trait: they provide a fair degree of mobility and forward momentum), and Life Strike in conjunction with tank builds (which can heal so rapidly that you can survive up to fairly high level content). There's also Chromatic Blade and endless Hysteria builds, but those are fundamentally ability builds which only incidentally involve melee (and as such are both very mobile).
Note that the only other time there has been a melee meta as strongly defined as slide-spinning was back before they removed coptering. It wasn't even particularly
good in terms of combat, but it provided an extreme degree of mobility in a time when melee was glacial and even normal movement was quite slow compared to the current movement system.
This is going to keep happening until all melee is brought up to the same degree of mobility that you can achieve with guns and abilities. When there's no good high-mobility melee meta, people will just use whatever stance is best/Volt and mostly ignore it. When there is one, that will be used until it's nerfed. It's not a problem with MS, with slide attacks, or with the combo counter, it's a problem with standard melee and the overwhelming majority of stances being absolute dogshit that kill your clear speeds and kill
you if you're fighting anything dangerous.