Well, the K46CM and the K46CB is practically the same, the only thing different is the processor (an upgrade) and the discrete graphic (also an upgrade). Just make sure you have the correct NVIDIA generation sticker and you're set.

Yes, the closest rival would be the Vostro 5460. Unfortunately, thats not a model a lot of people stock outside of Kuala Lumpur, so the K46CB is practically the one we are pushing out a lot.

K46CB
Intel Core i5-3337U (1.8Ghz Turbo Max 2.7Ghz - 2 Core 4 Threads)
NVIDIA GT 740M 2GB DDR3 Dedicated RAM

K46CM
Core i5-3317U (1.7 Turbo to 2.6Ghz)
NVIDIA GeForce 635M 2GB Discrete RAM Display

Only difference between the two model, rest would be the same.