Ok, here's the situation. I'm paralyzed from neck down and bedridden and use a small hospital table to use my computer (late 2013 iMac) and other gear on. You can guess I'm limited with space. I have 2 of these Mercury Elite Pro external hard drives daisy chained on fw800 that's AC powered. I want to upgrade the drives but I want smaller size drives. Is there any downside/negative to using a bus powered external drive as regular everyday storage? I'm looking at 2 of these WD My Passport for Mac 2TB Portable External Hard Drive Storage USB 3.0 as replacements. Any advice or info is greatly appreciated.