By more advanced technique, I am referring to Federer style forehand. For me the acid test of whether one has learned the technique is to see if that player is able to consistently produce balls with relatively flat trajectory but also has lot of forward kicking spin, a la Federer's balls.
This technique is considerably different than the traditional Spanish technique, which tends to produce loopier balls that tends to sit up more. On the women's side, you see some Italian players like Erani and Stosor. On men's, every year, you see less and less of the players with this (Spanish) style, as it is already outdated and not very effective. Even on the Spanish side, you see more guys that play like Almagro and Verdasco that hit flatter balls but still with tremendous topspin.
I agree that it is a 2-way street. However, with this new technique, you can mitigate a lot of pitfalls of the Spanish technique and I believe it will hold up well against flat hitters. The reason for this is: one, your ball does not sit up for the flat hitters to attack, because it has lots of pace, depth, and movement/spin. Two, you are also able handle lower high pace flat balls easier with this technique.