Without question, Ubuntu-Builder is a winner for intermediate Ubuntu enthusiasts. While it lacks some of the overall functionality found with Remastersys, it does offer a slicker user interface and a more modern user experience. The overall features come down to the following:
Desktop environment - you can select which one you wish to use: Gnome, KDE, plus six other modern desktop environments are readily available.
Packages list - Choose which packages you want to include by default and which you can do without.
Sources.list - This is the area where you can add in any additional software sources you might wish to include. It's also the area where you'd 'comment out' anything you'd rather leave deactivated.
Synaptic and Console - Both of these are used for deeper levels of control, and customization when desired.
Install deb packages - Self-explanatory in that this is where the distributable ISO creator would add any deb packages they want included.
Ubiquity - Perhaps the coolest feature from this tool is the ability to completely customize the Ubiquity installer. During your distro installation make the text say whatever you wish. The possibilities are limitless.
The one thing that I really love about the Ubuntu-Builder utility is that if you find yourself completely lost, you can throw caution to the wind and simply use the wizard option for the software. This way, you know you're doing everything correctly. Ubuntu-Builder is an easy win for beginner to intermediate users. Advanced users will likely want to stick with UCK or Reconstructor.
Two apps are better than one
The one takeaway I have from this experience is that it's painfully simple to create a completely custom version of Ubuntu that is devoid of any Ubuntu trademark protected content. This means you're free to redistribute your work, without getting into legal snafus.
How cool would it be to create Ubuntu-based distros using your own images? It might even be a great branding tool for your workplace, depending on the needs of your business.
Key point: I see no reason why you couldn't use both Remastersys and Ubuntu-Builder together. Hear me out before coming to any final judgments here.
It is my opinion that the best customization option for intermediate Ubuntu enthusiasts comes from a marriage of both programs. Each application offers something unique, so using both programs to create the ultimate ISO is a neat idea.
Again, if you're an advanced enthusiast, UCK is the way to go. It provides more CLI time while still giving you plenty of control. Best of all, it supports the latest version of Ubuntu.
For the rest of us, try Ubuntu-Builder and/or Remastersys. Both applications are fantastic, intuitive and easy to use. The best part is you'll find creating a distro of your very own is a lot easier once you get the hang of these easy-to-use software tools.