drae - tell me about the combat in DA:I
The combat direction of Inquisition is continuing the trend of AAA RPGs, less turn-based more action. Does this make it a better or worse game? Not by itself, considering the number of complaints Origin got regarding its combat. Does this make it a better or worse RPG? Depends on how you define RPG. I could always take Sawyer's definition of an RPG and point to how it isn't dependant upon combat at all.
Whether the combat is "decent" depends on your prejudices. Most people are fine with it, it's the tactical cam which needs fixing.
drae - tell me how DA:I differs from the previous games
How it differs from DA:2? Better all-round. People will quote the lack of attributes in Inquisition compared to DA:2, these people conveniently forget how STUPID the attribute system in DA:2 was.
How it compares/differs from DA:Origins? I'm not going to go into detail, here's my points though.
Story - Origins was better
Characterisation - Inquisitions is better
Writing quality - about the same (this will differ depending on whether you are a plot oriented man, or a character oriented man)
Exploration - Inquisitions
Choice and Consequence - Origins had more choices affect the story, I feel Inquisitions affects your environment more.
Character customisation - Origins is better
Combat - Depends on what you want. Origins had a weightier RPG-based combat, but was often panned as boring. Inquisitions is actiony, but is panned as twitchy. I don't really like either, to be honest.
Tactical Cam - Origins... unless you play on Console, in which case Inquisitions
What else did you want to know?
drae - tell me how DA:I is the same as the previous games
It's Dragon Age. The setting is the same, the writing is the same, the lore is the same, the landscapes, the characters feel the same, there's no question it feels "Dragon Age-y". The only differences are your degree of character customisation, and you have more places to wander *shrugs*.