I like to have a couple TCs "just in case". If you're in a pinch and there isn't a 24/7 ATM near by you can almost always exchange them at the front desk of your hotel 24/7.

I compared a TC and an ATM transaction done on the same day once. A $100 TC was within a $1 of the ATM transaction from my community bank ($1 Fee /Transaction). However the TC was actually less than using my wife's Wells Fargo ATM card (+$5 Fee/Transaction). Your millage may vary.