I got the game after patch 2.0., which deeply altered game flow, was released.
I really love the game as it is now, but I always felt that the game had huge unrealized potential related to its underutilized but very clever mechanics - suppression, cover, enemy AI, and so on. I often try to emphasize these features on my builds, and do enjoy them, but nevertheless I feel they're somewhat "orphaned" by the game's current hectic pace.
In fact, I made a proposal for a tactical or "old-school" mode on a thread here with the aim of better showcasing these features:
I've been doing a bit of research on the original state of the game, and have gathered that the original gameplay flow was much more deliberate, focused in exploiting these unique and absolutely great features, and much closer to my dream of a tactics-ARPG. Some of the playerbase found it grating and predictably clamored for yet another Diablo III ADHD simulator, and the developer measured response was 2.0 (bear with me, I get there were legitimate concerns regarding pacing, and the result is admittedly still fun, but I'm a bit jaded about media/player orthodoxy and do enjoy slower-paced games).
My message to the developers is this: thank you for this great game, and specially for the innovative mix of features this game offers. I'm sad I wasn't here on the beginning of the journey, because I would have advocated for your design philosophy. Remain confident that the systems and ideas you developed for this game are robust, original and a breath of fresh air in a stale, ossified genre*.
Also, please consider any tweaks that may bridge the gap between the original release and the more hectic (but very fun) 2.0. My suggestions in the other thread are just a few ways to do it. And a simple thing: make "Single Keypress Cover Mode" off by default. It may seem silly, but the current default option is what turned off many people to the cover system.
P.S.: In case any developer still prowls these halls, I have a massive suggestions thread / wishful thinking wall-of-text ready to go.
(*) Particularly: smaller scale and slower pace (i.e. more importance to individual encounters and ability to follow individual actions), tactically-focused gameplay, complex enemy behavior (flanking, cover, grenade lobing, etc.), suppression both for player and enemies, tiered debuff system, cover system, inoculator (custom potions), customizable missions (in rewards and challenges), deeds that unlock related "perks" to customize your character, bite-sized mission structure, story relevant player choices, interactive/destructible environments, focus on atmosphere and sound design, robust but subtle itemization (no +5000% damage to "developer X" favorite skill).