Understanding volume manager

[AWC Maillists]

Ok,
I am trying out FC3 RC2... installing on two identically configured 
machines:

HP Proliant ml330 g3
768mb RAM
Adaptec Serial ATA RAID 2410SA Enclosure Kit
4 300GB SATA Maxtor drives configured as RAID5
I have not used the onboard IDE or the onboard IDE raid as they are evil 
non-standard beasts - but with the above RAID I'm not too upset.

Now I have a question about the new (to me) Volume Manager options when 
partitioning the drive.  In the past I would partition the drive as follows:
100mb -  /boot
15gb -  /
152mb  - swap partition
Remainder of drive - /home
With the above I can install a new OS easily by simply formatting the 
first three partitions and leaving the /home parition alone so the data 
is available with a fresh install.  BUT, I would never be able to resize 
the /home partition unless I wanted to delete the partition and lose the 
data on the partition.

Now with the LVM option I am thinking of doing the following:
Create 100mb /boot parition (outside of the volume)
Creating one Volume Group for the remainder of the array called:  RAID5Array
In that Group create three Logical Volume names:
   LinuxDrive =  /  =  15gb
   SwapFile = Swap partition  = 1520mb
   HomeDrive = /home  = Remainder of array  ~840gb

With this setup I should be able to the following:
- Resize any of the Logical Volume Names without destroying data
- Add a second RAID5 array - make it part of the RAID5Array and then add 
the new capacity to either a new Logical Volume Name or to expand one 
(or more) of the existing Logical Volumes to use the new storage 
capacity.  This can be done without destroying any data.

I just have some questions regarding this:
1)  Soooo, is my understanding of LVM correct, or am I missing something 
very important?
2)  Is these any performance hit with using LVM versus the older method 
of paritioning the hard drive?

If posting this query here is incorrect, I apologize, but Volumes are 
being created when your use "autopartition" during the install process 
in FC3.  (And FC2 did not create volumes during the autopartition 
stage... so I ignored it back then.)  So I thought I would ask here - 
but if I should ask this elsewhere I would appreciate being pointed in 
the correct direction.

Thanks.

--- Charles