LouisM's comment is correct, BUT is for the -11, It seams that they got there act together again. Although the sample numbers are small yet the DOA's/early failure rate looks promising. I was going get the same WD but in 640, but may get the Segate.
One diff - WD has 32 Meg cache vs Segate's 16 Meg Cache (unless you move up to the 750 Gig version - which newegg did not have in stock)
I'd go for the seagate, I think the 7200.12's dont have issues. The small sample of newegg reviews indicates this. As i have mentioned before i got the 1.5 tb and have had no issues so far. as far as the cache the 500 gb single platter density more than makes up for it.
I have used nothing but Seagate's for years but I just bought two new WD drives to replace the year old drives in my main machine. A Western Digital Caviar Black WD6401AALS and a Western Digital Caviar SE16 WD6400AAKS (Blue).
I originally bought the "Blue" to back up my Seagate ST3640323AS (32md cache) when the firmware issues appeared. I had such a bad experience with customer support (like nonexistent) it soured me on Seagate. I realize they were overwhelmed, but it took weeks to get them to answer my questions and after having two "cases" closed without getting my issues resolved, I gave up on them.
Last night I bought the WD 640 Black from Newegg and will be replacing the Seagate with it, the WD Blue I got as a backup will replace the second Seagate I had in my system.
All drives can fail but Seagate responded so badly to the firmware issue I no longer trust them. Some reports say 30% to 40% of the drives they sold had the problem, which can appear out of the blue and brick your unit. If they had handled it better I would still be using them.
The fact that they now have a 3 year warranty instead of the 5 year speaks volumes.
Ref warranty. Why I'm not particuarly concerned over 3 yr vs 5 yr warrenty.
The reason may simply be a cost reduction, especially with the finanally challeging times. For example say the know the drive should last 6 years, it cost them more to sell with a 5 Year warrenty than the same drive 3 year warrenty. It has to do with the stock levels of parts that are required maintain. Use to repair TVs, needed to replace a Picture tume for a customer so when to the warehouse and bought one. They brought it out set it on the counter. The price for the boob tube depended on the lenght of warrenty. Exact same tube was 40% higher with a 5 year warrent than with a 3 yr warrenty.
WHAT I am concerned about is that Seagate continued to sell a defective (-11) drive and tried to downplay the problem! the -12 looks like a return to a quality product - BUT insuffient same number/and lenght of time on the market to verify.
Only 24 newegg reviews on the -12's, But only 2 (8%) = 1 egg, Both for DOA's which could be do to poor handling/shipping as I seen a rise of comments to this effect (Other drives included). Disregared the 1 (4$) = 2 eggs as I think he was refering to a -11. said he owned it for 7 Months - don't think they have been out that long.
The WD black 640 G (32 M cache) is probably a safer choice. 240 Reviews, 15 (6%) = 1 egg & 4 (2%) = 2 eggs. Same comment on pis***poor packaging.
In terms of performance - I think the Seagate -12 wins. Have not seen any reviews comparing the -12 750Gig 32 Meg cache to the WD 640 w/32 Meg cache.
Here is more info in a Toms' thread. Unfortunatly it compares a single platter / 16 Meg cache to the WD 640, 2 platter, 32 meg cache.