I switched on my computer yesterday and found that Galaxy suddenly wanted to download the whole 63GB of this game all over again. I naturally paused this, since I wanted to actually play the game for the four hours or so I had after work, and after trying to start my latest savefile I found that this made the game instantly crash to desktop. The loading times were much shorter though, intrigued I started a new character, using all the knowledge I've gained from my last character to make an improved version.

So far the patch seems to work fine, I have noticed some alternate item placement, slightly different store inventory (no +1 rapier for Astarion #sadfangs) and the fact that if you change Shadowheart with disguise self and then tell her to go away, she vanishes forever and you no longer have a healer, which means that when you discover certain near-death druids you can't heal them.

Anyhow, does anyone know if the 63GB is mandatory or can I just wait until they release the next patch?
I don't care much about the save files.

the 63 G is file corruption caused by pushing untested patches... if you installed with Galaxy 2 and not the offline or G1 then what should happen now is the new [repaired patch] of about 50md downloads and scans you game files to repair the damage

after that your old savegames should load again as long as you don't change any other ui settings like swapping valk for dirrect X for example

But if I repair and roll back to last patch, will I be able to use the character I made?
Because otherwise I think I am going to finish the game first, and then apply the patch.

you will be able to make him as a new character but the save games from the other build are not going to load no... its actually a pretty simple edit to fix this issue