Rosetta fits remarkably well into my life. It is not easy leaving the house and kid, because I'm still nursing and therefore tethered. I could -- but I'd return to a clingy kid so I just don't bother. It is nice, therefore, to have stuff to do at home. But if I'm in earshot/eyesight of the kid, he is drawn like a magnet to me and whatever I'm doing, so it also has to be something I can do behind a door elsewhere in the house. So far, that has meant reading a book or the treadmill (or TV, but there's only so much of that I can take) or the computer. It's very easy to just waste a lot of time (and spend a lot of money) while on the computer, so it's really great to have a computer activity that does not cost (more) money and sustains my interest for whatever block of time I have available. One lesson is good for 5 minutes or so; I can rattle through these early units in a little over an hour (but I'm slowing down as I reach the limits of my knowledge/memory). I dug up the headphones, so I can do this while the kid is asleep, too.
In addition to fitting well into my life, and being very "sticky" (what I learn in this program seems to be readily available to utter to the child while playing with him, altho there's no telling what grammatical errors I make while away from something that will pull me up short when I make them), Rosetta is genuinely immersive. And I think using it in conjunction with a native/target-target/native dictionary would actually detract from the experience, never mind if you actually tried to make sense of what they are covering in a given lesson with the assistance of a native grammar. I can really see why there is a huge chunk of the language-learning audience out there that not only objects to the price of these products, but just loathes the structure.
I've drastically cut down on the number of exercises I'm doing per unit. I walk through the preview, keeping a lookout for words the spelling of which will trip me up. Then I go through the writing exercise (the typing one, not the tile one). Assuming I get at least 80%, and I never use the skip-this-one option (if I really can't figure it out, I bail out, return to the preview, figure out what it should be, and redo the typing exercise from the beginning), I assume that's Good Enough and move on to the next lesson, unless it's lesson 11, which is the sum-up of the unit. For that one, I go do the listening-only test (I prefer the four-pictures to choose, because you don't have to listen to the entire prompt so it's faster), and then do the typing test. As long as I get at least 90%, I figure I'm done with the unit and move on, because odds on my attention will lapse and I'll miss at least one that way.
Because I miss a lot of repetition this way, occasionally there's a word that's a bit mystifying. If I looked at the associated picture enough times, I would figure it out, but rather than bother, I found my basiswoordenboek (Dutch-Dutch dictionary aimed at, as near as I can tell, elementary school kids) and look it up in there. So far, I've been able to puzzle out the meaning of the word without too much shuffling through the dictionary looking up words in the definition ad absurdum (mind you, a fun and educational game in any language). And there's no lapsing back into English (well, not any more than happens in my head no matter what I do).
As I think I mentioned in an earlier post, I worked through the Hugo _Dutch in Three Months_ book several years ago preparing for my first trip to the Netherlands, so a lot of this is revision, and I'm not too startled by any of the word order/grammar. That said, I took some German more recently than I studied Dutch, and they are somewhat confused in my head. Obviously, I can remember not to capitalize nouns in Dutch, but the this/these and which words, for example, are close enough to make trouble for me (and I don't just mean spelling them!). Some of the idiomatic question structures are also slightly different in confusingly similar ways. And I don't know that I have ever had a really solid handle on adjectival endings. BUT there is no effort to teach a rule here -- they just give you salient examples when the thing is first introduced, and then include more examples from then on while presenting more bits and pieces. So you get a bit more adjectival ending practice when colors are introduced, height, shape, clothing, etc. I'm not sure (I've only been at this for a few days) but I think this might actually do a good job of creating a feel for how to do the adjectival endings, rather than teaching a rule and having to cobble it together in my head consciously. That seems to be happening already, but it could be an illusion fostered by the highly controlled immersive environment of the software.
All positive so far -- I've got no complaints at all about this software. I do understand that it might bug the heck out of people who are attached to a different style of language learning (if you really want to understand the grammar now, for example, or the repetition is driving you bananen). This style of in-person class would make me nuts because it would go too slow, but on the computer, I don't have to wait.