Downgrade OS question

I just read the How to about downgrading the OS here http://crackberry.com/how-downgrade-...erating-system

I have a few question:

1. Generally, this process can make damage to the device performances/speed etc. after a few times of upgrading and downgrading?

2. Why its important to use jl_cmder to wipe my device before installing the os? can device be downgraded without that wipe?

3. I saw there are some problems with jl_cmder and vista 64 bit. i didnt catch how to solve this here http://forums.crackberry.com/f3/how-...l_cmder-53502/ ill appreciate if you can make it more clear to me.

Thanks :)

1. Different OS's, whether they be 4.6 or 5.0 builds, will result in different performances on the device. I have never heard of the total number of times upgrading/downgrading the OS resulting in damage to the device.

2. Wiping a device for many results in a more stable upgrade/downgrade. Wiping of the device is not necessary, however, I perform one faithfully with each upgrade/downgrade.

3. If you are experiencing issues with jl_cmder I would suggest using BBSAK. It is a more comprehensive application that also includes a wipe feature.