I'd agree that better is subjective. Maybe I'm looking at it wrong but despite coming bundled in kit form the alien is like any other mod. It's half of the equation, the other being the tank or atomizer. If someone likes a cleito then they like the tank. Aside from maybe differences in tc (dna vs fsk vs yihi etc), feature variations, theoretically the cleito should work the same at the same wattage ranges whether it's on an istick, alien, coolfire4, ipv8 etc. The wattages would be the same (hopefully) from one device to another for a given tank/coil resistance.
Which tank to use comes down to preference. Whichever you enjoy the flavor of, the features of (airflow, juiceflow, filling convenience) the most. It depends if you want to stick with tanks that use factory coils or something with a rebuildable deck where you fit your own coils and wick it yourself.
I recently made a few purchases, the alien being one of them. The settings and features are a little different, the shape's a bit different but otherwise it works much like my istick tc100w. It holds 2 batteries and offers decent variety of both tc and power modes along with memory settings and tcr. It works well with both atty's I bought with it, the ammit rta (single coil) and the avocado 24 bottom airflow clone (single/dual coil options) which is more of an rdta.
Aside from how they fill and the build decks, the bigger difference is the builds in them. Both those atomizers work/perform similarly on the istick as they do the alien. May not be of interest to you though since they don't use factory coils like the cleito or baby beast.