i have it and i am happy except that the bottles r so small. u have 20 ppl over for shabbos, 2 or 3 bottles aint gonna cut it.
when thinking about models, keep in mind that the basic one doesnt have any electric component so u can use it on shabbos and yom tov.
i think it would be nice to see how much air u have left in ur canister but the pros of filling on shabbos outweigh it.
they also sell the canisters at bbb if u want to buy a second one.
it may be a drop more money up front with bbb, but u always have the returning option which is great