A little of both. Peso are better when going to the hotel store, then they won't try to rip you off. I like american for tipping, and excursions. We base or trip on 100.00/per day and if we stay are the resort the bartenders get lots of tips. If we leave then less for them that day. Just a note we leave, it's usually Steve Boobs Cruise so a win/win.
We tip in US $ and allocate about $50 per day. Some days are more some are less depending on what we are doing, where we eat and the like but it averages out to about $50. Good idea to have some Pesos for any purchases due to the nasty exchange rate you will get at most places...especially the gift shop.
We usually take US $1.00 and $5.00 bills for tipping...we don't take anything more than $20.00 bills in US money. Peso we get different amounts again depending on what we are doing.
