I go to Tenerife every year Funster. Golf Del Sur is average except for the links of the 3 9 holes. I like Amarilla, a right good test of straight hitting but the greens were pish last year.
Adeje is probably the best course and yes, in winter that's the going rate.
We tend to block book and you can usually wangle a deal, especially now as the island is not half as busy as it used to be.