If you have the 160 GB
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tv, and have a large number of videos to sync, then for the
first sync, I'd use wired, then switch to wireless. (Unless, of course, it is trivially easy to plug it in to wired. I'm assuming that for wired you'll have to do some work, whereas wireless would be easy.)
And 802.11(whatever) generally gets about 1/3 its 'rated' speed as an absolute maximum. 802.11n's 300 Mbps, in reality, can just barely keep up with 100 Mbps Ethernet. It doesn't exceed it, though, in any circumstances. (Even a computer-to-computer 300 Mbps connection would be slightly slower than a crossover Ethernet at 100 Mbps.) And, of course, if you have anything other than an absolutely perfect signal, you will get even worse.
But for streaming, it doesn't matter at all, 802.11g's theoretical max 54 Mbps (realistic 20 Mbps,) is plenty fast for streaming video, the highest bitrate of which the
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tv supports is a measly 5 Mbps. It only matters for syncing, so for the first big sync, I'd use wired, then for the 'update' syncs, I'd just stick with wireless.