He's been very successful after leaving DM. He's amazingly talented, and without the split we wouldn't have Erasure or the sound of DM wouldn't be like it is today. Sometimes splits can be for the best. :)
Apart from his collaborations with Martyn Ware and the pre Yazoo singles. What has he done under his own name? I only know of the track What a wonderful world. Most songs in the chart list are totally unknown to me!