As you say sargassum is entirely dependent on season you are traveling and the current weather conditions. Off shore baffles have been installed along the malecon which have been somewhat successful. Beach clubs outside the malecon do not have this protection.
We have enjoyed Maya Chan several times. As I stated above, it could be a good choice solo provided you are comfortable walking outside port to the meeting place for transportation alone, or with others from your roll call. Although transport is “included in price”, it is not from within the port area. Also, depending on mobility, it is a long walk within the port and then a short distance outside.
Certainly once you are there it is vendor and hassle free, compared to the malecon. Service, food and drinks are very good. Food is local-cooked Mayan-style taco buffet. Sea conditions and sargassum are variable and outside their control.
One word of caution. Our last visit we had late, short port hours. To try and make the most of our time we opted for their last recommended taxi back. Unfortunately the taxi was late arriving and we returned to port much too late for comfort considering the long walk back through the port from taxi drop off (which is at port entrance on return). I would not be comfortable taking their last taxi again especially considering the distance, road and weather conditions - there would have been no contingency for breakdowns. Therefore I would recommend that you are not be too complacent regarding them getting you back in “plenty of time”. Ultimately the decision of which taxi to take is your responsibility. They will come round half-way through the afternoon and offer you a choice of times to sign up for.