My players are power gamers in general. From a mathematical standpoint, most of the mechanics were inferior to what is offered elsewhere. If you have players that either aren't concerned about the math behind the mechanics or are unable to determine superior options, then you'll probably be ok. In my case, if I can't create a character concept that equals or exceeds an available option for the majority of material with this early a release, it's on my no buy list. I found the mechanics in the SCAG to be inferior to what I could create using the PHB for the majority of options. The Bladesinger being one of the worst offenders. You could make a better Bladesinger with an Eldritch Knight or a wizard/fighter hybrid.
And having played a monk before, I find the Death Monk problematic because the monk will not land many killing blows due to inferior damage and the requirement he be in melee. Sun Soul monk could be fun and interesting providing some ranged attacking. But if you an archer in the group, the monk is sort of a third wheel waste of time.
Storm Sorcerer is somewhere between Dragon and Wild Mage, closer to Dragon Sorcerer with a nice high level ability. The Shadow Sorcerer's mechanics were much more powerful within a group.
Provable in play and on paper mechanical viability is extremely important to me. The monk archetypes would probably be ok in my book if I had not played one in a group with an archer and a warlock/fighter. My damage and defenses were inferior in nearly every way. I rarely landed death blows because of it. I was useless with ranged attacks. My group liked to take advantage of their superior ranged capabilities to take things down as often as possible. It was pretty rare that ranged wasn't a vastly superior option to melee. Close-Quarters Combat fighting style pretty much made ranged better than melee in any way very early on. I'm allowing its use right now, but I do hope maybe they look at that Fighting Style again and modify it some. Way too good.