Update: water beads!!The kids got some water beads for Christmas along side of these tubes and we hydrated them the other day and I decided to set up a marble set with them just to see how it went. Although it was hard to build because the tiles were wet so more slippery and less stable, it was over all a success. The water beads don’t go down at smoothly but they do go down to a certain extent and the kids love putting the squishy water beads through the marble run. I’m sure you can get them all sorts of places but we got our water beads from amazon and they came in a pack of over twenty thousand which I accidentally rehydrated the whole lot and we had tons more than we needed. We filled a whole bin with them and built a magnet set right in it. It gets messy but it’s still fun!Summary: Amazing product, the tubes add extra support to your magnetic tiles by snapping into place, the kids love it, the marble runs are a little tedious to build for little hands but with assistance from an adult this can be a fun activity for you and your kids to enjoy as it is for us, I would recommend getting at least two marble run sets and a large tile set to really be able to build freely.For reference, what you see pictured is a tower we made using pieces from the following sets74 piece magna tiles100 piece Picasso tiles2 Picasso tile marble run sets80 piece Picasso race car track setAnd we had more tiles to to make it bigger if we wanted..Comparison.. We own Picasso and magnatiles and both are very similar in quality. The Picasso tiles are cheaper andI believe they are cheaper because they don’t use rivets and they have less support in between the layers. I have yet to see any issues but I would think that because of this the magnatiles are probably more durable. I guess time will tell. Considering the Picasso tiles are almost half the price, I’d recommend Picasso unless you have serious durability concerns.As for the marble run, it’s literally incredible. An amazing addition that is compatible with both magnatiles and Picasso and probably others I would imagine. We have a lot of fun building huge marble run creations as tall as me using our multiple sets of tiles and also two sets of the marble run. I would definitely recommend at least two marble run sets. I actually want to get a couple more because we tend to run out of the turn pieces quicker than I’d like. (By the way the turn pieces can be doubled up to act as down/up ramps if you turn the the doubles turn piece “tunnels” to be vertical).Also when you add the marble run tubes to your tiles, they snap into place, without magnetic force, which is actually super awesome because it adds an extra amount of sturdiness to your creation when you have a marble run going through it. In fact if your kids don’t care for marble runs this is still a cool set because you could use these pieces to strengthen up your towers and creations.The pieces that have to be snapped together are sometimes a little difficult to complete for little hands but with practice my 5 year old was able to do it ok. Sometimes it requires a really both gentle and forceful touch to get them into place without knocking over your tower but that’s where the adult comes into place. I don’t think this would be something anyone younger than five could completely independently but after built they surely could play with it.It comes with plenty of balls to run through, but yes normal marbles will work on it too for the most part, although marbles are more like to jump off after a steep decline and a turn (can be fixed by doubling up the turn pieces to create a turn tunnel of course).We also got a marble run that is compatible with duplos (also from amazon, to find just search duplo marble run) which is way cool but this is even better because The long pieces can be doubled up and placed vertically to make your marble run enormous unlike the DUPLO style marble run. But also the duplo style plastic “marbles” will fit in this magnet marble run too. Was thinking about creating a duplo marble run that runs right into this one! The possibilities are almost limitless.The kids love building and running marbles through it.. but if you have young ones that like to destroy, despite the added support of the marble run tubes snapped into place, the set can be completely demolished in a matter of seconds with a not very careful (or somewhat rambunctious) toddler :).Over all highly recommend, it was an immediate hit with the kids for Christmas and I have no doubt that this set will provide fun for years to come.