I can't speak for Danny or Mike, nor would I, but I can try to give you an articulate answer to your question from my perspective.
For me, although there is no set formula that I follow, there are several basic criteria that come into play when I determine what items I would like to choose for review.
Has an item been heavily advertised in the industry? If so, I think the readers deserve to know if the item lives up to its' advertising, or if it's just hype. Is the item something that has not been advertised at all, yet I think it might be something the readers should know about? Perhaps an item would be great for the kidshow worker, but totally useless for the part-time finger flicker. "It" may be a neat addition to the working repertoire of the full-time, professional trade show act, but of no value to anyone else. It doesn't have to always be a blockbuster of an effect, either. Whether it is a trick, routine or gimmick, if it seems like it has been targeted for, or may have some value to a certain group, I will try to give it the space in the column. Of course, as I mentioned above, this does not guarantee a positive review.
If an item has been targeted for a certain type of performer, I will review it from that target audience's perspective - not just whether or not I would use it. In other words, I am not going to review "Binky, The Balloon-Eating Polka Dot Magic Clown That Sneezes" children's effect from the eyes of a corporate hospitality suite worker. I will take a look at it's value, or lack there of, from the view of a kidshow performer. This holds true for all of my reviews.
Another consideration for me is variety. I have done, and will continue to do my best to mix up the collection of effects for review each month. This includes close-up, stage, mentalism, kids, etc., from both known and unknown people in the industry. This means, I may have to hold onto a review for a couple of months, because there are already two card tricks reviewed, and I would rather include a stage effect, instead of another card review this month. Genii's readership is a very diverse group. At one time, I was a frustrated reader of reviews in magic magazines, because they all seemed to either review just card tricks, or tricks from famous people only. It amazed me that all the famous people's items got rave reviews, and the unknowns were the only ones who got bad reviews of their products. When I choose to review something, I keep this in mind, and try to avoid falling into that trap at all costs.
On the subject of "examining something carefully" - sometimes a quick "once-over" is all you really need. This is especially true if the item is a sleight variation on an already existing item (i.e., a new size thumb tip). But I learned very quickly (even before Danny Orleans' review of "Puff the Magic Dragon" that you mentioned), that maybe every item should get at least a "twice-over," in case I missed something. Rest assured, I will ALWAYS give multiple examinations to an item that I think will end up with an unfavorable review. If I am going to give a bad review of something, I want to make damn sure that I have tried it under all possible performing situations, and given it a chance to succeed. Then and only then do I feel confident that my reviews can be trusted by the readers. Readers may disagree with my reviews (many creators and distributors undoubtedly will), but they will at least trust that I am consistent and honest in my reviewing process.
One last thing I should mention, is advice. I am not afraid to ask my friends in the industry (professionals and amateurs alike) for their opinions on an item, if they've seen, bought or tried it. If I am unsure about an item being worthwhile for a mentalist, I may run it by my mentalist friends, and get a consensus from them. The review will still be from my perspective, but they may have a better take on it than I would, and this will greatly improve the accuracy of my reviews. On a similar note, my friends in the biz (performers, historians and fellow reviewers) are not, and have not been afraid to let me know when I've goofed on a review. (It's strange that they never tell me when I've written a good review.) Of course, that's why they have earned the title of "friend".
The "normal delay time," isn't. Items sent to the Genii office, get opened and photographed for the reviews. Then they are shipped to either Danny or me, for review. Again, not speaking for Danny, I will examine each item, give it a test-run, and write my review. From the day an item is sent in for review, it could take, on average, anywhere from one to around four months for it to appear in an issue of Genii (remember, Danny and I alternate months, too).
Of course, the short answer to your initial question is - It's all up to Richard. :D
Best Regards -