When I gave this to a friend they took quite a bit longer to solve it - due mostly to the little trick required half way through the solution. Putting it back took a whole lot longer! I do like this one to give to others - it is a bit tough but still doable with some thought. A lot of the pleasure of puzzles for me is the watching other people go through the solving process (with or without clues from me).
Finally in this review I tried the Sputnik. This is a variation on the old bent nails puzzle with the aim being to separate the 2 coils. It looks pretty simple until you realise that the diameter of the coils is just too small to allow the ends through. The beaded rings are more for decoration than anything else - they make the puzzle slightly more awkward but don't really add much more. This is a level 6 puzzle and I almost think it should be level 7 - I managed to extricate the coils from one another in a couple of minutes, but putting the damn thing back together again took me a further 10 to 15 minutes! There are a number of different ways you can start intertwining the coils and only the correct one gets you to the end. I ended up systematically trying each one and lo and behold it was the last one I tried!! The very last extrication movement is a bit tricky and I ended up backtracking several times before I fathomed it out! Oddly I actually found this puzzle to be very difficult to repeat - it has taken multiple solves before I can do it fluidly. All in all, a good puzzle - especially for the repeatability. I have given this to quite a few people now and most seem to struggle to open it but do manage it after 10 or 15 minutes. So far absolutely no-one has managed to put it back together! Despite warning them to keep a proper track of exit position none have really watched closely enough and then got stuck during re-assembly- it is easy to get a single piece intertwined but getting both pieces double intertwined has proved to be a barrier to everyone. This does make me feel a bit better about how long it took me!
Of these 4 I like the fourth one the best and would suggest that a version of the classic Handcuffs should be in every collector's possession.