The performance of the Tag and Lexicon (and Meridian) will destroy your Yamaha. The differnce is huge, though for substantial money. However if you are looking to upgrade so soon there must be something wrong with you dealer having sold you something that you don't want. Enjoy what you have for the time being. Your system is essentially balanced as it is. If you want to upgrade I would personally say Tag but all three are excellent. Go and find out for yourself. I did, it is the only way you will be happy with YOUR decision.