Am I one of the only mages that really like Rune of Power and enjoy placing it pre-emptively to blink onto if I need to move? I unno, it's pretty coo that way and the glyphed version of it (the evocation glyph) makes questing so much more easier than pre-90. By far. Like, I'm freaking out at how easy this talent makes my life. I use it on -everything-. I friggen use it when I'm standing around doing -NOTHING- because it looks -awesome-.
Okay, enough of that. I'm pretty sure that the invocation thing is cool and all but I never liked the whole, standing still for the cast time and all that. It's also probably a huge pain if you intend to keep max uptime on it, so you should probably avoid trying that for trash. I could see invocation being a really interesting thing for arcane given the link it has with mana so maybe it synchronizes there better, unfortunately I like RoP so much more because it has more mobility than Invocation.
Incanters ward is good for PvP in my opinion, easiest PvP talent out there to see. It's just alright in PvE, no reason to cry about it though if you're complaining about ease of use. Sure it's the 'easiest' to use, but if you want to use it correctly you'll want to find incoming damage (which is unavoidable many times). It'll probably be the talent for lazy people I find, given that RoP requires you to place them quite often and to get used to your blink range and invocation makes you sit still for so long.
Also, in very early stages of MoP, invocation did give you a 40% buff, however it was brought down to 25% since it was apparently too ridiculous at that point.
So far I've had no trouble using RoP in every situation other than getting used to it. My damage was low at first due to figuring out how to work with needed mobility on fights but most of the time I've never had to stand around waiting to put out a new RoP on a pull. Invocation seems like a pretty cool boss talent but I'm not seeing a real use on it for 100% trash uptime. My damage is slowly getting better as I get used to the new gimmicks which is what I expected, I'd be rather disappointed if I could just rip the charts fresh at 90 with non-forged gear from questing. I find doing decent AoE DPS also has a higher skill requirement now which is interesting.
Either way as GC has said like, 5 billion times, he wants our damage to scale with better gear so we actually feel like the gear matters and smooths out your rotation. We may not like it but that's how it's going. Either way, some of the 90 talents can be used almost all the time even for trash pulls I find. The only time I have an issue with mobility is when things get pulled too far for no reason (but melee have trouble with that too unless they're keen on the tanks movement, but then ranged could be too). Either way, I don't think there's too much wrong with them so long as we balance out with other classes, I think people were far too used to tossing out awesome damage as arcane by mashing a single button. I was one of them too though, so it's okay, we can hug it out.