Hey Cly,
I already installed To Go on a 16GB usb 2.0 stick and I can tell you the facts. It's up to you to decide if it's worth a shot or not.
Ok, the usb stick it's pretty standard. I posted the speed specs some time ago:
http://www.eightforums.com/installation-setup/5103-windows-8-go-usb-stick-2.html
I used CP x86 (32bit) following Wolfgang's procedure here
http://www.eightforums.com/tutorials/5349-windows-8-go-setup-usb-flash-drive-usb-disk-11.html more or less.
Then I formatted the stick and used RP x64 (64bit) following the same steps. Because 64bit programs should execute by a few percent faster, BUT the 64bit version has more files to copy and the imagex fase (copying all system to usb) took almost 120 minutes instead of the 32bit 90 minutes.
After copying files, it was bootloader time: I had a Win7 x64 base pc and the needed bcdboot command doesn't work here (usb not bootable). You need to run the command from within Win8 with the To Go stick inserted. So I set up a VM in VirtualBox /VMware where you install the needed Win8 version just for running the bcdboot command here with the usb stick inserted.
That went pretty well and it was testing time: you should boot the pc from the stick to see it run. Note that the best (fastest) computer in house is recommended because hardware has to be installed and the process takes a long time.
CP x86 (32bit) first boot: pretty slow the first boot time, about 50 minutes seriously.
The RP x64 was something similar but didn't measured the time, just left the room for an hour (that boring install screen took ages)
But was ready in about an hour. Yes it's usb 2.0. Be warned.
After the first boot I was impressed: the second boot was 2 minutes and later on almost 1 minute!
So if you got a spare usb stick give To Go a try.
The first boot on a second computer with the same stick goes fast: in less than 3 minutes you are on the desktop.
Installing apps, progs and stuff also goes slow. To speed thing up use offline installers already copied to a local HDD in the pc (if available) and run setup(s) from there. I did this with some programs and the nVidia installer: when the installer suggests extraction to C:, you pick your own desired HDD / sdd drive (not the To Go stick which is call drive C: here).
After some use and when your needed programs are installed, you can run them (still slow in comparison with a HDD or SSD but worth it for usb 2.0 stick)
Some users here used usb 3.0 sticks for To Go with better (or worse than expected) performances.
To Go works also on HDD's and SSD drives but for the cheapest solution, I leave To Go on my usb 2.0 stick.
I use it sometimes for the show or testing programs and apps on different pc's without the need of installing Win8 everywhere. It's a pretty mobile and flexible solution.
I now use the RP x64 To Go: the install took longer to complete but that's over and the benefit of x64 should be present. The disadvantage of x64 To Go is that older (32bit) processors and pc are not supported but that doesn't worry me since 90% of what I use here daily are 64bit capable pc's (pretty basic dual cores and a i5, not much) not a problem for the mobile usb stick here.
That's the story of a usb 2.0 To Go setup.
Thanks
Hopachi