The MS, as stated, will providea full assortment of hop-ups, so much it could even be considered a race chassis. This means tighter clearances, more adjustability, greater rigidity, precise handling, and lighter weight.

Though the IFS looks great, I have found that because there are more working parts in the system, it is prone to more slop. Instead of an upper and lower shock mount, you now have 4 pivot balls and a hinge. Each, having it's own imperfections, will add up to looser fitting final assemblies.
Most people upgrade, which will increase costs. A full build with quality parts (TRF, 3Racing, Square) will often cost more than the top shelp kit. In the long run, a simple purchase of the top-shelf car at the start will make driving more rewarding, and you forgo the upgrade process.