I had a blast playing multiplayer. In total, I've spent about 6 hours with it so far, playing a Human Adept, Turian Sentinel and a Female Vanguard.
Pros:
-Map layouts
-Customization and progression
-Graphics & Sound design
-Enemy variety
-Objectives (Hacking, Assasination, Extraction etc)
-Length (An average 11-wave match is about 30 minutes, which is perfect for me)
-Ease of UI navigation
Cons:
-Minor bugs
-Race unlock system. It is not very good. What is so exciting about unlocking "Human Female Vanguard", especially when I already HAVE a female vanguard? It should be based on progression. Level up adept class, and you unlock asari.
-Lack of story. I suspect we'll get the full picture once we play through the singleplayer, but I do wish there was a little bit of story attached to the levels, or at least a description of these areas we're fighting for. As it is right now, we are just random soldiers plopped into an area and told to "get it back", which is fine... but I would like a little more description of the areas at least.
-Lack of squad commands. I will be playing co-op with my friends, but not all of the time. I will be using PUGs on xbox live, most without mics, and it would make co-ordination a lot easier if we had squad commands, such as "Attack this Target", "Follow Me", "Retreat" etc. I thought I saw something like this on the controller screen, but I couldn't get it to work.
-Lack of bosses. I think bosses should be in. The mechs definetly fit the bill, but I think it would be very cool to have actually bosses, maybe on the fifth and tenth wave. Like a special phantom that cloaks around and stealth kills everyone (creepy!), or a cerberus captain that has special abilities. And we get special rewards based on how fast we can kill them. That'd be cool.
But all in all, I love the multiplayer. I wasn't expecting much, and I came away very impressed. Montreal team really outdid themselves with this and I look forward to the launch of it.