Thanks for your message and questions !
> If I run a test and it identifies bad sectors and remaps them, what happens if I repartition,
> re-format or change the type (mbr to GPT) of the drive? will the bad sectors stay hidden?
The bad sectors (if they properly identified and re-mapped) never cause further problems. All further reads and writes are re-directed to spare area, so the original bad area will never be re-used. Even if you re-partition / re-format the drive, the bad sectors will not cause any further problems.
Please click on the "?" button next to text description, it describes the above
and give further information about the current situation.
Also the following pages may help:
http://www.hdsentinel.com/faq.php#health
http://www.hdsentinel.com/faq.php#tests
http://www.hdsentinel.com/faq_repair_ha ... _drive.php
> Will any operation destroy the remapping?
No, they remain for the rest of the lifetime of the hard disk.
> I just used western digital's dlgdiag because I was told that the manufacturers software would always be better than 3rd
> party software at testing the drive. Is this true?
No
Sorry to say but it is absolutely not true.
The tool released by the manufacturer does not care about hard disk problems and especially they do not care about the stored data on the drives.
The tool you mentioned is designed only to verify if the number of problems reach the error-level threshold set by the manufacturer - and then you may ask for warranty replacement. But they do not care if the data is accessible, if the performance is degraded, if there may be special test methods required to reveal and fix problems. If you check the number and detailed information and options of hard disk tests available in Hard Disk Sentinel, you can see this is much different compared to tools provided by the manufacturer.
I mean that even during simple testing (Disk -> Read test) the software monitors slowly and hardly accessible areas, monitors actual performance, reports any (even minor) degradations of disk status and so.
In most situations, tools offered by manufacturers perform some limited testing and maybe a zero-fill. These are also availble in Hard Disk Sentinel - but as you may see, Hard Disk Sentinel offers much more testing options. For example Disk -> Surface test -> Reinitialise Disk Surface to properly fix weak sectors as described at
http://www.hdsentinel.com/hard_disk_cas ... ectors.php
> Even if so, I still love HDsentinel for all the other functions it provides.
Thanks!!