I don't know which is the best kind of service on Palawan, whether it's SMART or GLOBE. In other parts of the Philippines, it is difficult to choose between them. Possibly GLOBE just shade it. I have all three types of SIM card Smart, Globe and Sun so I am in quite a good position to compare them, it seems to me GLOBE might do just a tad better with connectivity, sometimes SMART seems to fall short at seafront locations where there is a sharp drop down to the shore down a mountain. A few times I've found there to be no SMART signal, but OK GLOBE. More often than the times when there has been no GLOBE, but OK SMART.
what you want to do is as soon as you get to a mall, go to a decent phone shop and ask for GLOBE Pocket Wifi. THere is two kinds, a 888 peso one and a 1500 odd peso one that is supposed to be faster than the 888 peso one. However I found the cheaper one to be really rather good, good enough to watch YouTube videos more or less anywhere whenever I wanted.
if you only have one device, you'll need a dual SIM phone for this as the pocket WiFi has a data-only SIM. It's for internet only. It is not for making calls and text messages as well.
load for so-called unlimited service (and the pocket WiFi can operate up to 10 devices) costs 50 pesos per day, 85 pesos for 2 days, 200 for 5 days, or 1000 a month. I've never had any problems with it. Just get talking to them in any decent city phone shop about it.