i went last year with Ciclos Uno, an east London cycle shop that organises training camps mostly for Essex clubs. We went in February and were lucky with the weather for the first week: it was mostly dry and mild, and by delaying the start of the ride on one or two days we didn’t get rained on at all. However, there was snow in the second week, so you can get unlucky with the weather.
We stayed at Porta Pollensa: the terrain at this end of the island was great; we could choose between going to the mountains or flatter, rolling terrain. The road surfaces were very good, although slippery after it had rained: apparently they are known for this.
My advice would be to go easy on the food, especially if your trip includes half board with a buffet evening meal. You might need to eat a bit more than ususal, but many people stuffed themselves and put on weight…