Just that the standard lemon tree will get up to 75% larger than a dwarf and require a HUGE pot if you plan to let it grow all the way to it's potential. I hope you have high ceilings as well! LOL! Good Luck,
Matt

I figured I'd cope with the growing-too-big problem later. If it's healthy enough to get 12 feet tall, maybe I can find a local business that wants an impressive lemon tree in its lobby.

Being in a pot naturally limits growth. Root and branch pruning will keep it from living in a lobby. A woman once posted here about a lemon tree 50 years old from seed. It was only eight feet tall and living in a 18 inch pot. The care is the same.

If it is a common commerical lemon (Eureka or Lisbon) then the growth pattern will be more towards taller than wide. What size pot you grow the tree in will have a great deal with how big the tree gets. You dont have to keep moving it up to larger containesr as the tree grows, if you wish to keep it at a managable size. - Millet