Huh, never seen that thread... [/sarcasm]
I know this thread is old, but for anyone else still looking... I agree with what has been said about picking a battery line and sticking with it for cordless.
For years I had Dewalt 18v cordless tools (pre-lithium ion era). The batteries crapped out shortly after Dewalt switched to the 20v max line. I was too ticked to buy new 18v batteries assuming the 18v tools would die off and the 20v max tools were too new to have many options. I also didn't want to be stuck with 20v max tools if they flopped and were discontinued quickly. I used the opportunity to sell what I had and switched to Milwaukee. No complaints.
You really can't go wrong with either. Milwaukee seems to have more tool options, especially in the 12v, but
if you need a cordless miter saw Milwaukee doesn't make one (in the US). The same could be said for something Milwaukee makes and Dewalt doesn't. Look at both lines and pick the one that offers everything you think you might need.
For corded tools I typically will buy the brand that is best known for whatever tool I need or whatever brand I can get the best deal on (as long as it's one of the major brands). My router and table saw are Bosch, jig saw and angle grinder Dewalt, rotary tool and multitools Dremel, and miter saw Ridgid. All have been great and work as needed. Anything Tool Shop brand from Menards should only be purchased if you need it for one project and never again. Even then, it may not make it through the project...