Let me begin by saying: Not even close.
Now let me elaborate a little. Yes, DS9 has had its ups and downs. And for all intents and purposes, I definitely feel that seasons 1 -3 are not on the same level as seasons 4 - 7. Having said that, it's easy to forget all the great material in those early seasons (e.g. Emissary, Duet, the Circle Trilogy, Through the Looking Glass / Improbably Cause, to name but a few highlights). In the final analysis, I think the good easily outweighs the bad.
What's really important to that is that there was already very strong character building going on in the first three seasons. You really got to know these people. And it was really interesting to see them get involved in the unfolding conflict / war. Also, the DS9 universe is being mapped out very strongly in those seasons, in particular with reference to Bajor and Cardassia. It is a reach playing field that would benefit the show later on.
If you look at DS9 from start to finish, although it's not as strongly serialized as, for example, B5 or nuBSG, you can clearly see how very much the characters as well as the universe itself change throughout. And they don't just change 'for fun'. There are events and developments that take place which clearly lead from one point to the other. That's very rewarding to watch and give the show a lot of rewatch value, I think.
Another point is that the show had a very, very strong writing staff. Yes, they could misfire. But when they were on a roll, they were incredible IMHO. You'd have multiple episodes dealing with multiple storylines at times, and it would feel like they were juggling them ever so easily. You know it's a good thing when an episode cuts away from one storyline and you're not annoyed but rivetted because you want to know how that storyline continues as well...
I watched and enjoyed S3 of ENT. I have to point out that at that point I had already given up on the show and was watching, really, for pure Trek nostalgia. I wanted some new Trek, and that's what was there.
There are a number of reasons why I gave up on the show in the first place (this is relevant to the thread so I will quickly elaborate). First of all, none of the characters appealed to me. Even the doctor (though I probably still liked him most next to Trip) never managed to engage me the way the other Trek doctors did. They all just seemed incredibly bland, and you never really knew who they were. Worst of all, I found the captain incredibly bland and unconvincing as a figure of authority even though I really like Bakula and was looking forward to him in the part.
Essentially, you'd see the characters interact on the screen, but it never felt vibrant or alive to me. It felt like hollow shells saying stuff that had no relevance to them or the others or the show itself, for that matter.
As for the show itself, well, it just seemed to have no point, nothing that truly set it apart from TNG or VOY. And that's a shame since the setting SHOULD have really set it apart. But the show never seemed interested in that.
Instead of using the building of the Federation and Starfleet as a focal point around everything else could naturally evolve, you had the usual space exploration and weird aliens along with lots of bickering between humans and Vulcans. The ship and its crew were literally going nowhere.
To make matters worse, I felt the writing was really, really bad, atrocious, in fact. I found myself having a really hard time sitting through many of the episodes because it felt so embarassing to watch. And some episodes I didn't sit through as a consequence.
So my starting point for ENT S3 was not a very good one. And the main problem - one that just wasn't resolvable from my point of view - was that the characters were already too far gone. The first two seasons had damaged them beyond redemption in my book.
Watching S3 I basically chose to ignore seasons 1 and 2 as best I could. But, naturally, that also meant that there was no real backstory to these people (there isn't with seasons 1 and 2 either IMHO, but that's another matter). So while it was fun watching them go through the motions, it never stood the chance of being able to involve me the way DS9 was able to season through season. DS9 benefitted from its own hard work. ENT faltered due to a lack of it (note: I'm not referring to the writers directly. It's very possible the creative staff on ENT worked very, very hard).
As I watched ENT S3 I just wondered why they didn't start like this. DS9 had given them precedent. And they had a backstory that fit very well with serialized storytelling. But, alas, this was S3 and not the beginning of the show.
The story told throughout S3 was definitely engaging and had some pretty tough moments for the crew. I remember the Captain deciding to pillage another ship, for example, or T'Pol and her addiction. Those were interesting moments because they really challenged many 'Trek' assumptions and dealt with morally and ethically difficult subjects.
And yet, as a whole, I clearly felt this never came close to what DS9 was doing. Yes, it was good story, yes it was well told. But DS9 had an excellent story and was excellently told, in my view anyway.
So while ENT S3 was entertaining and certainly more fun than bad DS9, it never even came close to good or great DS9 for me. Too much damaged had been done by S1 and S2. And without a backstory built throughout the seasons, it just felt a lot weaker than it could have. I'd also argue that the writing was ok and sometimes pretty good. But I felt it never excelled much like the show itself never excelled IMHO.
I've actually never seen S4 of ENT. Who knows? Maybe someday I will. But really, there isn't that much making me want to. Another bout of nostalgia may do the trick. But ENT on its own hasn't really done enough for me to want to revisited that particular part of Trek lore. And as I've said with respect to S3, I feel the characters have simply been damaged beyond repair. I just can't watch them and take them seriously as characters.
And what good is a show if the characters do nothing for you?