OPTIMAL Filesystem / Allocation unit size to use for PORTABLE APPS?

I've decided to format my flash media on several computers and reinstall the latest PORTABLE APPS pre release 4.1.Im going to be running it from the following:

512 mb Micro SD card
2 GB Micro SD card
1 GB USB flash drive

So what is the most efficient format option for each scenario (since since each is dependant on drive size)

FAT (FAT16)
FAT32
NTFS
exFAT

Also what allocation size should I use for the clusters?

4k,16k,32k, ......512k,1024k, .....ETC,ETC

I have read this post https://portableapps.com/node/15053

and many other threads on here.But they all seem to wander off with extraneous info about benchmarking,post-install encryption,filesystem conversion,etc

Im already some what knowledgeable about all this stuff,so Id prefer a short summarized opinion about what you think is the best option.Perhaps even just an example of what you have yours formated to and allocated as.Maybe even a roll call of the following setup your using

what type drive are you using? card or drive?
what size is it?
is it SD,or SDHC?
what format did you use?
what cluster size did you use?