I fried my shredded potatoes forever and they still didn't crisp up. That is, until I followed the advice given here and bought a CucinaPro 313 Ricer/Spaetzle press for $9.94 from Amazon. When I pressed the shreds, I couldn't believe how much water came out. No wonder my hash browns stayed soggy and wouldn't fry up crisp.
I agree. Russets are fine. You can also par-cook the potatoes prior to frying in a few tablespoons of hot oil.