The part you're asking me to delete is mostly a direct quote of William's review. Plus, I honestly feel like those factors need to be carefully considered before making the purchase. For the magician buying this with a specific idea in mind they need to realize that the effect has to be structured a specific way and that their idea will not work out if they can't meet that criteria.
That said, I feel the product is very good and is brimming with potential. Portal is a nice effect as is and I could see people getting plenty of mileage just from that. I think personally, I'm more likely to get my 50 bucks worth through incorporating this device into effects I already perform. Designing effects around it and incorporating into routines you already perform will just require some critical thinking but thats nothing new for magicians (or it shouldn't be anyway).
Also, the production quality of the gimmick didn't really strike me as poor or anything like that. I've never seen one of these before so I don't what would make for a good one of these...things. It feels solid to me though and I don't foresee having any problems with it.
I'd recommend this mostly to people who either:
A: Love the effect of portal. (And it can be damn good. Consider that you would then have the perfect opener anytime you see someone who happens to be smoking.)
B: You are a performing creator and have good critical thinking skills to use for designing effects around this gimmick and/or incorporating it into already established routines.