Reception was fine around Manila, although there was enough dropout for it to be noticeable. Palawan wasn't any better (especially Sabang and even El Nido), and neither was Coron town. However, I actually had better reception when island-hopping around Coron. Obviously this is due to there being more open area for signal, and not being blocked by buildings. So just be aware of the somewhat weak but manageable reception - it's a third-world country after all, so expectations should be tempered. Just connect to your hotel wifi to plan ahead for anything important!