ME1's narrative structure (the "BioWare formula") isn't a desirable model at all.
You sacrifice the story's pacing, progression, and integration of characters all on the altar of having the barest illusion of choice of choosing which order to complete a list of plot coupons in.
It's not an illusion. There are very few "must do now" missions in ME1. How your character decides to prioritize and approach them has a huge payoff for role-playing.
Enforced pacing is not a desirable trait in a game. It's great in a 2-hour movie, not a 40+ hour game where the player ultimately controls the pacing, anyway. There are few things I dislike more than having some major plot point revealed or an oh-so-urgent mission assigned or some oh-the-drama! sequence of cutscenes start playing just as I need to log out for the night... or answer the phone... or run an errand... or whatever. The net result is that unless the player has a big enough uninterrupted chunk of time to finish a complete playthrough, the player has to actively resist the game's attempt to enforce pacing.
The availability of quests became so tightly controlled in ME2, they had to assign a yeoman to stand right next to Shepard and manage her appointment book. Boo.
With only a few minor modifications (which the game does not prevent the player from headcanoning), ME1 would be just about perfect:
-- Lose the "race against time" terminology wrt finding Saren
-- Give the collections missions more plot relevance. The Matriarch's writings, League of One Medallions, etc. could be rumored to include some encoded information vital to stopping Saren - and in some of my playthroughs, they were.
-- Oh, and lose the mini-game. If I have someone qualified to hack or decrypt in the party, it should happen without the player needing to pass some skill test.
I really hated the way a lot of missions started in ME3 - having the team dropped off right in the middle of a hot zone, in full view of enemy combatants. Not only did it mean the team had zero opportunity to assess the situation, plan tactics, set up ammo loads, etc., but it also made Shepard feel like a complete idiot with a death wish - and the enemies lame for having allowed them to arrive alive.
Pacing... pffft.