Comment 14 for bug 156177

@Evan

There is no need to determine size for /home and for /

You simply offer to create 10 GB for root and if there is between 512MB and 1.5GB ram you offer to double that for swap and if there is 2+ you offer to equal the size for swap and just make those values changeable.

EX:
"Ubuntu recommends creating a separate /home partition, typically a user would only need 10GB space for / and XGB for swap. Would you like to use the following configuration?"
(make these user changable)
[10 GB] /
[X GB] Swap

Very straight forward and won't confuse a newb as it is ubuntu recommended.

In fact I would first greet with an option to:
1. Keep existing OS and install Ubuntu along side (as dual boot)
2. Just install Ubuntu (you will have the option to migrate your data if you choose this setting)

VERY SIMPLE AND EASILY UNDERSTANDABLE
IMO less confusing than being greeted with a large bar that is all one color and options that people don't understand. JUST TELL THEM WHAT IS RECOMMENDED FOR THE TYPICAL USER