Madison XT = mobility radeon HD 5750
M2 means MXM II certified. It means your graphics card is MXM II certified and can be upgraded with any MXM II certified card. MXM stands for Mobile PCI Express Module.
But the thing is mobility Radeon HD 5750 is no where near to desktop HD 5750, it is actually a overclocked HD 5650 with GDDR5 memory support.
But the laptop uou mentioned, does not have DDR5 graphics memory, it is having GDDR3 memory. So don't expect very high performance.
The price of the Laptop you mentioned is almost 49k. If you wanna a gaming laptop, why are you spending that much money? go for Acer 5740G, the best gaming laptop within 50k. It is the best laptop at the budget and have positive reviews by all the sites. I personally have tested this machine.
Price is around 43k
Basic config is
Core i5 420M
4 GB DDR3 1066 MHz
500 GB 5400 rpm SATA
1 GB HD 5650 GDDR3
1.3 Mpx Cam
4 USB
15.6" display with 1366X768
3 Hrs Battery life
2.8 Kg
This laptop is able to play all the current games with High or Medium-High setting without any problem. Even Crysis is playable with high setting with avg 30 fps.