nope. using sata2 seagate on a sata 1 mobo. the extra 16mb buffer does make a big difference with 8mb buffer. transfer rate is considerably faster. no lags on my com.

for the airplane noise that you mention, its a sign that the hard disk is going to fail so backup. if it frequently sounds like that when you're using.

if you hate noise there are other alternatives. silent fans are the solution. if you can't do a direct HD cooling, you can opt for case cooling measures. moderating the internal temperature is one way of cooling the hard disk indirectly

not sure about the jumper thing. cause i'm using a sata 1 connector to a sata 2 hard disk. since it work, i don't bother to scrutinize the whole functionality of the component. may be you can ask others to confirm it.

just discovered something, seagate has the worst fitness. mine is on the edge of breakdown. 1 of it is constantly showing symptom of breaking down. based on the figures, both my seagates have lowest spin retry count and the most terrible seek retry rate. so stay away from seagate. they cannot handle to much stress as compared to maxtor and WD.