Well, I recently tried out my first Mayhem Mission (finally!) and wrote up my comments on it elsewhere. But I thought I'd port them here so they might actually be useful, maybe. So here we go:
I finally get a Mayhem Mission from Kara the Scorpion. Rob a bank in Steel Canyon. I enter SC in an instance that starts just a tad north of the southern Tram with lots and LOTS of tab-able objects. Parking meters, boxes, barrels, cars, CIVILIANS. On the one hand the sheer amount of stuff to destroy was pretty neat. On the other, trying to tab your way to actual enemies becomes a HUGE pain, and pretty much impossible out in the main city. Another problem came up when my pets went absolutely ballistic in certain parts, so much so that I really had to keep them on Passive until I had something targeted for them to beat up, and sometimes even then they wouldn't obey my orders, or run around blindly for a few moments before doing what I want them to do. (Oh hey, that Longbow Eagle is hovoring over a fence, I think we should run all the way to the END of the fence to jump up on top of it, it's only 400 yards!) Also, while Civilians are targetable, you can't actually HURT them. My zombies beat the snot out of one for a bit, but his health bar didn't even flinch. Typically, when attacked Civilians run straight to the nearest building/entrance. I think you DO get bonus time for 'terrorizing' the populace, but you can't actually beat them down. Pity. This actually becomes a bit annoying when you get to the actual bank robbery, all the civilians in there are ALSO targetable, though you can't do anything to them, so trying to tab through all of them to fight the actual GUARDS is a bit of a pain.
Anyway, I get to cause a fair bit of carnage while cutting a swath to the bank, though I don't unlock any 'side' missions, I was mainly focused on just getting to the objective, and seeing how it plays out. The bank in Steel Canyon is formatted a bit differently than the ones on the Rogue Isles, so it's nice that they didn't just slap another coat of paint on the ones from CoV. There's an elevator to the second floor, where the vault is, and this time the glowie to get the loot isn't an instant thing, it has a 'countdown' like other glowies in the game do. Once I got the loot, well, I wasn't expecting company so SOON. When I made it back up to the first floor I was suddenly jumped by an Elite boss. Not one of the signature heroes, this guy was Doc Quantum, I recall meeting him once in the CoV cape mission. However I quickly realized the battle with him was going VERY badly, as he was totally fixated on attacking my Mastermind, totally ignoring my minions. That's bad news for any MM. But not unexpected, since it's how most, if not all, ambushes operate, so I just wasn't expecting to run into him so fast. I won't make that mistake again. After getting my health knocked down to a tiny sliver of bleeping redness I manage to use all my respites, and drop a Tar Patch, and hit the Doc with Darkest Night. Then I hid behind a file cabinet until my Zombies were through with him. Mission accomplished.
I explored a bit more, but left the mission soon after when I ran into a SWAT Grenadier. It IS nice to see the police of Paragon cut back the slack, though. Anyway, my overall thoughts are as follows:
The devs should code in a way to use Tab to only cycle enemies, so if I want to get the destructable objects I can, if I just want to hit the things that are actually a threat I can.
We should be able to do SOMETHING to the civilians. I can understand that having the game allow you to willfully kill civilians would drive up its rating, but we should at least be able to knock them out, or otherwise eliminate them from being a target, at the very least for convenience sake.
Mastermind pet AI needs to be tweaked a bit regarding their priorities in Mayhem Missions (hell, it needs to be tweaked anyway, but there it was particularly bad). Even when I gave orders they sometimes completely ignored the target I was giving to them, and almost always ignored the 'GoTo' command which is pretty bad.
I guess the level of hero that comes to stop you depends on how much Mayhem you've caused, and what level you happen to be. Hellscape was only Lv23, so I wouldn't expect the Freedom Phalanx to send one of their members to stop her. They probably become more frequent in the later levels. I didn't cause a lot of carnage this time around either, nor did I find any optional missions. Yet. It was my first go at the Mayhem Missions, so I'll get the hang of them eventually.
I get the feeling this is something my Brute will enjoy a lot more. Basically because he won't have to worry about pets, and can just smash whatever he feels like, at his own pace. The Mayhem Missions still seem to be a bit trickey for Masterminds. However, we CAN just head straight to the bank/heist and get it over with quickly if we decide. It gets the job done, though where's the fun in that? It seems that you'll get an Elite boss thrown at you either way, though, I'm not sure yet if they get bumped down to Lieutenants on the lowest setting. They SHOULD, especially since you can be given Mayhem Missions in the Lv5-10 range in Port Oakes, and you won't even have Dual Origins at that point, so Elite Boss = Nasty.
I've seen posts of people encountering Back Alley Brawler, Positron, and Valkeryie in Mayhem Missions. I somehow doubt that Statesman will show up in one, but hey, y'never know. It's only been on test for a few days, no one's picked them apart enough yet, I guess.
Anyway, bottom line, Mayhem Missions still need to be tweaked a bit, but they're a very nice addition to the CoX gameplay.