The opener for Season 4 takes the whole bloated flatulent beast that was the temporal cold war storyline and finishes it up in two episodes. The finale doesn't necessarily make a lot of sense, but it rockets along nicely and gets rid of the poison chalace quickly so the show can get on with telling some interesting stories rather than the same old crap.
The next episode "Home" deals with the crew back on Earth having a well earned rest after all that's occurred. Not a mind-blowingly brilliant episode, but watchable, which immediately places it above most of the first season I saw. And the ending avoids all the predictable cliches that it could have been lumbered with.
I had to skip the next three because the first was a faulty download and I found I actually cared about seeing it. Yes, it was the first of a three part storyline, but I wouldn't have cared with the previous seasons.
The next storyline "The Forge" has plenty of political intrigue and good old-fashioned character work tied in with a chunk of Star Trek history. I've got one episode to go in the storyline and am flat out not watching it immediately. It really is that good.
The quick version is, I'm actually enjoying Enterprise. If the show had been this well-written at the beginning, I would have tuned in every week. So far, well worth a look.