Here's my mbx-5 w/ a 9xl, mm esc on 4s and it weighs a little over 9 lbs. and it still screams!!!
http://www.rc-monster.com/forum/showthread.php?t=11763
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S