Hi Rafael, I hope you enjoy Malapascua as we did. I would like to go back. We stayed at Ocean Vida and used Sea Explorers. Keep in mind that these are two separate 'businesses'. No issues with either one.
For the diving, just sign up early for the Kimud shoal dive as that tend to fill up fast. Kalanggaman dive is another site I like. That's a full day trip with BBQ lunch offered by the DMs. There's an extra charge for the lunch. It used to be 500php. Don't know how much it is now. We had a 'full board' package and Ocean Vida worked it out with Sea Explorers so that we don't have to pay extra for the BBQ lunch.
Keeping in mind that we are a 'mature' trio with plenty of dives under our belts, Lydio was assigned as our dive guide. I don't know if that was by design or it just happened. But, we love Lydio. I noticed that he steered us away from the 'crowd' on each dive and each of our dive was 'calm' (not rushed) and beautiful and with plenty of photo ops. I don't think we missed anything. Our dives were usually more than 60 minutes, and we're usually the last ones to surface. We did not have much interaction with the other dive guides, so can't make comparisons.
Have some Philippine pesos ready. If not, there is the ATM on site (if not broken),another one in town, or you can make some currency exchange at the dive shop. I don't know how much is the limit and the x-change rate. I remember it was fairly reasonable though.