I just ordered a 30mm, I like the idea of the small dot but talking to the Ultradot Lady in CA (the importers I guess), I asked if the smaller dot would ever be available in the 30mm & it appears it will not be.
We all have different needs and preferences but for me the larger tube is more important than the smaller dot as I will not be shooting my SRH further than 100 yds. at game, esp. Deer or Black Bear. An adult Buck will have a 16" or so chest, so the dot would be 1/4 of body mass & I can use the bottom dot for 2" OF the drop, so not all bad.