I did my divemaster course in Roatan an stay there for a while, basically all dives in Roatan (Utila as well) are wall dives and very few dive sites you´ll find any current, water temperature is 26 (the coldest you get) to 29 Celsius, visibility is excellent about 25-30m and sometimes above. The corals are in ok condition (you cannot say the same for Utilas corals) as there is a Marine Park Reserve (you´ll have to pay an insignificant fee to help the conservation of Roatan MArine Park). Marine Life have decresed (but still ok) in recent years as in many places in the Caribbean due to invasion of the Lion Fish a foreign specie in the CAribbean (originally from the PAcific Ocean) and the overpopulation of divers. All in all is a good diving destination in the Caribbean, a you´ll enjoy it, the tourist town is West End this is where you´ll find most of the diving operators, restaurants, Marine Park Office, etc.. but there´s no swiming beach (theres half moon bay beach a nice beach but crowed with diving boats). If you are planning to do some beach activity besides diving you´ll have to stay in West Bay next to West End it´s little more expensive but the beach it´s beautiful! (or take a cab from West End very cheap). I can highly recommend Coconut tree Divers the best dive operarotor in Raotan, excellent instructors/divemasters very profesionals and secure, plus they have cheap beer (cheaper than any bar or market) in a fridge that opens 4 pm after the last dive, you can chat with other divers about your last dive at dive shop wooden deck with a cold beer in hand as you watch the sun set over the beatiful half moon bay. A plus for notrhamerican tourists is that altough Roatan is part of Honduras all the people speak fluent english (in fact english is the native language and everything here is near,the dive shops, dive sites, restaurants so you´ll do all your travel using your own feet (except you want to know other towns in the island). But Roatan is a place to spend no more tham 10 days as you wont have much to do beside diving and the dives tends to get repetitive beyond that time (remember is all WALL DIVE). Go there have a great time perfect your diving skill and save some vacations days for your next trip to philippines.
Philippines is one of the top diving destinations in the world, so diving is no where near as diving in Roatan in terms of coral conditions and marine life abundance, but theres a lot of diving destinations and beautiful beaches insides Philippines (Remember it´s a 7107 islands archipielago) "so´ll need more than a month of time to spend to make this trip worth. Another thing many english speaking tourist seems to ignore is that altough english is the second official language most philippinos speak little to no english (with the exception of tour operators and tourist bussiness people), so you´ll have to manage to make yourself understand. But as others said in this post diving is cheap (if your sallary is in dollars) and one of the best you´ll find in the world."
Well enough said. Hope this helps. Have a great time diving wherever you choose to go!