I think story-arcs are a preferred way of showing the theme of a show over the course of a season or seasons. I do not think the story-arcs of Enterprise were all that fantastic, just middle of the road (Temporal Cold War, Xindi, etc.), and I liked Enterprise, more so than the average Trek fan.
The arcs that dealt with the foundations of the Federation and the Romulans were by far more dramatic, mostly because I felt a connection to it and I understood it. Unfortunately, it came too late.
But when the show delved more into simple episodic story-telling, much like how TOS was, I found myself enjoying the premise of ENT far more. Granted, most of the time they did this it fell flat, but there were times where they nailed it (Season 2 comes to mind: Carbon Creek, Minefield, Dead-Stop).
Enterprise, to me, had the best premise of any of the series, it just did not deliver.