There is no 7200.12 with 1.5TB size and never was. Some websites speculate Seagate may release one, but currently the 1.5TB Seagates are the 7200.11 (firmware problems) or 5900.12 (5900rpm, low power). You have misidentified your troubled product, and you have now misinformed & confused others. You should be more careful & accurate when you badmouth a product.
It's silly to drop Seagate b/c of one troubled product like the 7200.11. If you look at storagereview.com you will clearly see that every disk manufacturer WD, Hitachi, Fujitsu, Maxtor have had "klinker" product families. When it becomes a pattern then it might make sense, but that is not the case for Seagate. WD is IMO worse, and Hitachi has had more spectacular disk-family failures.
Also important to me is that the 7200.11 fiasco was due to firmware and not a mechanical issue. It appears that Seagate shipped the original 7200.11s with a firmware problem that could cause permanent failure. The first updated firmware had an equally evil bug. Reports indicate the 3rd firmware set for this family is fine, but I have no direct experience. I'd rather just avoid that line and get the lower power and generally higher performance 7200.12s
It's also the reason you should do some homework before buying any drive. The customer reviews of newegg or the forums of storagereview would have allowed you to easily avoid your bad experience.