I can second SailCaribe for the SVIs. We chartered from them a little over a year ago and had a great trip. Good (and growing) fleet of Lagoon cats and Jeanneau monos. Easier to get to than the Virgin Islands (particularly the BVIs) and more convenient if you are planning on staying in the SVIs. We didn't spend much time in the SVIs as we were trying to sail from Puerto Rico to the BVIs and back in ten days - which I wouldn't recommend unless you are focused mostly on the sailing. In any case, from what we did see it was more relaxed and less crowded, but also not as many options when it comes to dining and shopping. Also, as Sail2wind mentioned, no real infrastructure for resupplying once you leave Fajardo, so stock up before you leave and ration your water usage. We didn't find navigation too tough, but there is plenty to watch out for. Keep a close eye on the chartplotter and verify by paper chart and visual fixes when things might be close.