I'm sure Meera wouldn't mind.
As for your question, I suppose it was a few things. 1) I think that there is a TON of Japanese in みんなの日本語. The Lesson book is exclusively in Japanese and most of the workbooks are 95% in Japanese, if they aren't totally in Japanese. Genki has soooo much English it's a bit annoying to me personally.
2) The text gives me a good challenge because of all the Japanese and forcing me to recall all the grammar and vocab from the grammar/vocab book (which is the only book in the set that has a bunch of English).
3) I also like the size of the lessons a bit better. They are smaller, and I feel they are less bogged down then Genki. A typical lesson in MnN is about 4 pages in the lesson book, and about 4 pages in the grammar book (excluding the workbooks here). In Genki a typical lesson is around 20 pages long.
4)The grammar is more throughly explained in Genki, but I find the "bitesized" explanations in MnN more my style and just as effective as their Genki counter parts. I don't feel as though I need as much of the explanation that Genki gives. To me at least, it seems like the two textbooks are trying to get to the same place on a subject, but Genki takes the long way. MnN is like, here it is, now see how it works in the exercises, example sentences, and the dialogues. It's a lot more inductive.
Short version: I like the use of a TON of Japanese in the MnN materials, and the lesson size. And it's a more inductive textbook.
It just depends on what you're looking for as to which you would want to go with. Genki holds your hand more, while MnN challenges you more. The cost might also be a factor, as Genki is about 60~70$ for the textbook and workbook where as for everything for the Beginner I materials for MnN you're looking at an easy 100$, if not a bit more.
I could PM you a few links for you try them both out, if you wanted. Nothing beats seeing for yourself.
United States (United States) 
. I thought for sure I had my own Japanese thread, but after much searching I guess I don't. Anyway I am making this thread to help keep myself motivated in Japanese and to help with some of the mistakes I constantly make and maybe try to write simple journals. I am still a beginner in Japanese and currently working through Genki 2. So I will be posting my Japanese updates and questions here. But my Japanese is not very good, so there will be lots of mistakes. I am trying to focus on Japanese and Korean while I have some free time this summer. 
). They are really fun too, they have good vocabulary, vocabulary that I find I use a lot or hear a lot, they have some good cultural references in there and the set up is pretty good. I would definitely get the workbook with it 
Canada (Canada)