Ill start out in LL because LL has been consistently giving me 4-5 leves at the counter per set and 4/5 would be worth doing. Uldah might have 2/4 leves 10 or more ranks below me as well as Gridania. But dont neglect the other two cities. SP is SP

You dont necessarily use the facility as a boost to success, facilities remove the restrictions certain recipes have. Just like if it tells you that you need fishcleaning, or confectionary, etc etc. If you dont have those, you have to battle your success rate with those restrictions. The leve will tell you what facility is required before you actually pull your tool out and I have yet to get a leve that tells me I need Masters so I dont use it.