If you look at my earlier posts, I never indicated that ALL card tricks are to be avoided. I was specifically referring to those pick a card, name a card tricks. By the sound of it, Sankey's Bigger Finish may not fall into that category. Instead, Bigger Finish seems to rely on visual incongruity instead of mental recall and recognition.
If so, this would be similar to Color Monte - the kids simply need to recognize the red diamonds and the blue diamond (These are shapes and sizes that even very young children can recognize and therefore relate to). The visual incongruity of the $14 card is very strong can be very strong and effective. Would this same trick be as effective with two Queens and an Ace? I don't think so. At least not for very young audiences.
The key is that the trick has to be within the intellectual ability of the age group for whom you are performing and they have to be able to relate to the props being used. It is for these two reasons that many/most card tricks fall flat for younger kids.
Even in Bigger Finish, kids may recognize and respond to the incongruity that they see at the end of the trick. But how much stronger would the trick be for the same group of younger kids if the cards used images that they could relate to? Over the years, I have learnt that you not only strive for impact, you strive for maximum impact in any effect that you perform.
As for building an effect such as Bigger Finish into my show, it would have to meet several additional criteria above and beyond being a good effect. Whenever I perform a show, there is a presentational theme to the show. Every effect I perform has to fit into that presentational theme. This allows for smooth transitions, a higher level of entertainment value, and a much more professional show.
In addition, the entertainment value of the effect must extend beyond the trick itself. This is extremely hard to describe in a short post like this. Suffice it to say that the road leading to the finish of the trick has to be just as, if not more, entertaining than the rest of the trick itself.
Again, just one person's opinion