Originally Posted by HKGhost
You'll end up upgrading those CM guns and it will end up costing the same as the Top Tech, but without some of the cool features. Quality doesn't come in cheap, but personally I rather wait and save up for the better buy. It's your money so I can't tell you what to do. Just my 2 cent.
You don't need to upgrade them at all, they're great out of the box. However if you're willing to spend the money, then get the Toptech version.