Tried it myself. Although it's a hassle to put a new Custom Rom on the phone because you lose all your data this tutorial really works!
My only problem was that DiskPart cleaned my SD Card but didn't want to create a partition. I had to remove and reinsert the MicroSDHC card, clean it again and then it worked like a charm.
+1 for making this a sticky. Could be extremely useful to lots of users and the rom that is used is available on all HTC 1st gen devices.
Device: Sony Xperia Z C6603 black 16GB with 64GB Sandisk microSDXC card
Rom: NamelessROM
Recovery: TWRP