I don't mind the side-quests and the RPG-iness of the first game.
I do think that they should have kept a few things from the first game in how a character levels up though instead of dialing it down to biotic abilities and weapons damage - tech hacking skills etc. probably should have/could have been kept - and a limited (instead of infinite) inventory would be good for exploratory purposes.
The side-quest buggy tank driving missions in ME1 were a bit of a drag though (to go all over the map to find a base and then shoot everything in it (the interiors were rather copy/pasted as well).
That was the only part that was a bit tedious - not to mention going through all of those hills and whatnot.