Jorge,

Yes I did and it works fantastic!

The stock 1900mAh NiCd packs produce short flights when performing aerobatic maneuvers. I would typically get about a 5 minute flight depending upon the amount of aerobatics performed. I replaced the stock ESC with a JES030 Jeti 30 Amp Microprocessor Motor Controller from Hobby Lobby to try the 3-cell Kokam 3.2AH pack which would provide 150% flight time with 2-cells more power and an incredible weight loss of 6.5oz! The 3-cell Lithium pack hop-up not only lightened the Magister but provided longer more spirited performance.

Something to consider once you have improved your flying skills from trainer to intermediate level.

If RCU doesn't post my review soon, i'll post a link to my unformatted submission here.

[link=http://www.hobby-lobby.com/jeti.htm]JES030 Jeti 30 Amp Microprocessor Motor Controller[/link]

[link=http://www.hobby-lobby.com/kokam.htm]FM32003 Kokam 3 Cell 11.1V, 3200 mAh LiPoly Pack[/link]

or

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXJSJ2&P=ML]FMA Direct/Kokam 3-Cell 3200mAh Pack w/Deans Connector[/link]