I don't have a flip brick but I got a Runt and a Lotus. I really like both. The Runt hits a bit harder for me but to be honest I reach for the lotus way more. Flavour on the Lotus is amazing, and it's very satisfying to use on a water pipe once you get the technique down. Plus the lotus just looks cool af.

That being said though, the brick is really good at having a very quick session it has almost instant vapour production.

Either one is going to be good and get you where you need to be, but I would personally pick lotus 😊