I seem to be getting the patch right now as I'm writing this(knock on wood), but this has been a hassle, and a hassle just to get the thing downloaded is something that I don't need and one that I don't like having forced on me.
And when we had the stand alone patch, we had a whole different set of "hassles" to deal with such as...
People screaming how large the file was, how long it was taking to download it (another nice thing about Impulse is that it automatically distributes the load amongst servers all around the world -- if you're in Europe, Impulse will grab the files from local European servers).
People who downloaded a 600 megabyte patch from some third party site only to discover that we did another update a few days later that they then had to download another 600 megabyte patch.
The things we make that have been using Impulse (or SDC before it) often get multiple updates PER MONTH.
We released GalCiv 2.0 last week for instance and we have 2.01 ready to go which is just new features and improvements to the game.
If it were a stand alone patch, we'd have to give everyone a 500+ megabyte patch. The 2.01 update will likely be less than 2 megs because of Impulse.
So yea, there are a handful - and I mean that literally - a handful of people who have had trouble getting Impulse going.
Most of those people ran into problems because of the web installer we used which we replaced yesterday - hours after discovery.
There's a second group of people running into problems logging on which we should have corrected shortly.
But I would say that Impulse works perfectly for 99.9% of users right now and within the next few days, it'll work on 99.99% of users.