Hi. Well it souly depends whether your comparing the MSI to the "Pure" or "Duluxe" version of the Asus card. Ok, the "Pure" version uses 4ns (capable of 500mhz) and 3.6ns (capable of 555mhz) rated TSOPS memory depending on whether you have the 64mb or 128mb version, and all this is loaded on the tpyical Ti4200 short 6 layered PCB, as like the MSI GF4 Ti4200. Although, if your comparing the MSI to the "Duluxe" version of the Asus GF4 Ti4200, your in a totally different ball game. The "Duluxe" uses 128mb of very fast 3.3ns (capable of 606mhz) BGA memory which is loaded on the longer 8 layered PCB in which the bigger brotheres Ti4400/4600's sport (See Picture below). Think about this too, most more expensive Ti4400's use slower 3.6ns memory, and also the Ti4400 core/memory clocks are 275/550mhz. Now listen to the core/memory clocks of the Asus "Duluxe" GF4 Ti4200....260/550mhz, a difference of only 15mhz on the core. But now listen to the core/memory clocks of the MSI and any other typical GF4 Ti4200.....250/444(500)mhz depending on whether you have the higher clocked 64mb or lower clocked 128mb version. Now, for paying around £10 (£15) more for the Asus "Duluxe" GF4 Ti4200 than the typical Ti4200, but at the same time not paying the £30-50 premium for the Ti4400, I think your getting a rather good deal indeed, and bare in mind that the Asus "Duluxe" also does have faster rated memory (3.3ns) than most typical more expensive Ti4400 cards! Also, due to the cards extremely fast memory, when OCed, the default 550mhz, should go straight to 606mhz garanteed, and then 630+mhz, and near to £250+ Ti4600 territory. The core too should go straight to 300mhz as it's merely the NV25 GPU that the Ti4600's use, but the difference being it's clocked 40mhz lower (260mhz as opposed to the Ti4000's 300mhz), then the core should go 300+mhz. At HardOCP, they managed to OC this cards core/memory clocks to 310/640mhz, and was able to match/outperform a genuine Ti4600 card Check out the full review
http://www.hardocp.com/article.html?art=MzMx if you want there is also a MSI review on the same site
http://www.hardocp.com/article.html?art=MzI0 Now think about it, a £150 card outperforming/performing the same as a $250+ card is amazing, and your saving a lot too (around £100). I'd strongly consider this card if you can obtain one. But yes, if your comparing the Asus "Pure" Ti4200 to the MSI GF4 Ti4200, then I agree, go for the MSI, but if it's the "Duluxe"......go for that.
The PCB design of the Ti4400/4600's in the Asus "Duluxe" GF4 Ti4200
The typical GF4 Ti4200 design of the MSI GF4 Ti4200