I will say I saw a gel ant farm at someone's house once and it did LOOK very cool. I could see it being an interesting introduction to young kids - though frankly, I think dirt/sand set-ups are better and less gross for that purpose, though not as "space ship" like.
I would NEVER use one for a colony with a queen. Even with just workers I feel bad for them. Having recently bought some of those Uncle Milton ants, I watched the Pogonomyrmex working and grooming each other and burying their dead one by one. The only good thing is they are wild-caught and so the ones who get caught are generally older and have lived out happier days in the ant nursery.
Past & Present
Veromessor pergandei, andrei, stoddardi; Novomessor cockerelli
Camponotus fragilis, Camponotus sansabeanus (inactive), vicinus, laevigatus/quercicola, CA02
Pogonomyrmex subnitidus, P. californicus (inactive)
Liometopum occidentale (inactive); Prenolepis imparis; Myrmecocystus mexicanus (inactive); Tetramorium sp. (inactive); Lasius sp.
Termites: Zootermopsis angusticollis, and a box of drywood termites that can't be seen
Isopods: (most no longer keeping) A. gestroi, granulatum, kluugi, maculatum, vulgare; C. murina; P. hoffmannseggi, P. haasi, P. ornatus; V. parvus, P. pruinosus, T. tomentosa
Spoods: (no longer keeping) Phidippus sp., other