It may have to do with the formatting style, ext4 is a modern file system, while NTFS has been around for ages. In fact, many XP install media, by itself, cannot reformat a drive back to NTFS from ext4 (it'll crash during format), a partitioning tool has to be used first to reformat to NTFS, then re-attempt the XP install.
Could be that the ext4 file system fixed any sectors that weren't badly damaged (or the drive needed a good wipe) & that's why Linux installs fine on older drives. As far as running afterwards goes, yes it's going to run better, due to the lack of needed overhead. Many times my 64 bit Linux MInt 17 uses less than 700MB at idle. Security on Windows alone would use that much, if not more. This leaves more resources for when using the machine, and it'll feel more powerful, because the OS alone isn't using hogging the resources. Kind of like on older vehicles, there are ways to dramatically improve performance, with dual exhausts being one of the first.
However this doesn't, nor is meant to imply not to replace, or at least have another HDD ready to go for when the day comes that it does go, along with regular Data backups. The OS is replaceable, one's Data isn't, and Data recovery is costly. Fortunately, for many LInux users, the Data backup isn't too large.
These days, hard drives are back to all time lows, with some great SATA 3 performance drives in the $50-60 range & 5 Year warranty (WD Black series). For $10 less on the same size drive, there's the Caviar Blue line, but only has a 2 year warranty. It's worth the extra to have the 5 year warranty, plus the massive 64MB cache vs.16MB on Caviar Blue. That's 4x larger a cache for massive load speeds. For those with drives of 8MB cache installed, it's an 8x increase. Unfortunately, few machines won't make full use of the SATA 3 speeds with a HDD, but the cache will be used & noticed.
Secondly, many 120-128GB SSD's are frequently on promo for $75 or less, and if one really wants the ultimate in performance, especially on a SATA 3 motherboard, it's worth the little extra cash & just grab any promo drive for Data & backup. Many times, one will have an extra drive laying around, which can be used for these & virtual machines, which are not recommended to be ran on consumer grade SSD's. There are major differences in speed & pricing between home/enthusiast and commercial SSD's & the gap is widening.
Even on a SATA 2 motherboard, a Linux OS will fly with an SSD installed, however one must setup TRIM & enable some other performance enhancments. Today's SSD's doesn't need to be pampered, but TRIM is a must, otherwise performance will over time degrade to that of an early 2000 model IDE HDD. However, the settings are no big deal, a little prepping with the Terminal will make & keep the SSD performing great for years. Probably longer than the rest of the computer, if a quality SSD is purchased.
And for those who already has SSD's installed, here's a quick way to restore performance at anytime, though this is the manual way (copy/paste), using the Terminal. Your password will be asked for.
sudo fstrim -v /
If /home partition is installed, also run afterwards:
sudo fstrim -v /home
You'll see how many bytes are Trimmed (deleted & reclaimed for use) each time this is ran & I run manual Trim in addition to whatever the Automatic is doing behind the scenes.
I'm currently running Linux Mint 17 on two computers with SSD's & never would want to look back to spinners, they're quickly becoming storage, rather than OS drives on newer computers & I'd say that come this time next year, that number will at a minimum, double. Most any SATA computer will benefit from a SSD upgrade, and like I stated, doesn't have to break the back. For older models, there's a budget Kingston V300 that should work well, as these aren't the fastest anyway.
As always, please check system prior to upgrades & don't sink lots of cash in too old of a computer. For PC's, a "desktop kit" isn't always needed, and sometimes doesn't fit. Velcro hold SSD's in place fine, that's how light they are.