boot off of SD or internal storage?

I have never used the internal storage on my Pandora, always opting to boot off of an SD card thinking if I use the internal storage it will wear out. Anyone else have this concern?
yes me.
i opened many threads about this. this is the last one
but maybe my problem is not exactly as you described.
since i was too lazy to send my unit back, i kept it and use a SD card to boot from.
I honestly don't see the problem. If you never use the internal storage then yes, it will never wear out, but then you're not using it so why even have it? You use an SD card, it wears out, you get a new SD card, and repeat, meanwhile the NAND remains pristine... for what?
If you use the internal storage and it wears out early and you need to switch to SD cards you are not any worse off than you were just using the SD cards and ignoring the internal storage; plus you get to take full advantage of all the benefits that come with using internal storage vs external cards. And there's not really a risk of it breaking anyway, so there's that. In the choice between "use internal storage and risk wearing it out" vs "never use it, only use external SD cards" the answer is obviously "use the internal storage until it wears out"
That being said, the flash is rated for tens of thousands of writes, and between proper wear leveling and the fact that the average use case doesn't see a lot of writes to the "OS drive" as it were you shouldn't have anything to worry about. This may change with the Pyra: the Pandora's flash only stored the OS files, with all programs and (presumably) file storage on SD cards. The Pyra has a sufficiently large internal storage space that I can foresee the use case changing and people installing stuff and storing files directly. Whether this changed use case will make a difference or not I can't honestly guess, but I would stake a small claim on the Pandora being safe to use.

@ahahah, your problem is different; you probably had a bad unit. It happens, no process is 100% perfect, it failed early, unlikely to be a result of excessive writes, it was just bad memory.
I have seen and been amused by this behavior in other areas too.

*People who don't 'live in' their homes for fear of damaging resale value. They will remodel with stuff they don't like because some day it might make it easier to sell. People install Jacuzzi bath tubs then use the separate shower, granite counter tops that have never had food on them, fancy designer ovens that are never used, etc..
*I've seen 4WD vehicles with bull bars and winches on the front who refuse to brace the bull bar on a tree during winch loads (a standard practice - does not hurt the tree) for fear of scuffing the powder coat (paint) on the bar.
*Buying the thinnest possible of smart phones with Gorilla Glass screens and IPV6 waterproofing only to then double their thickness with a rubberized plastic case and plastic screen protectors that trap water/gunk and cloud over the screen.
*Refusing to use the NAND on a Pandora for fear of wearing it out.

It is part of a mindset that I'm amused by but do not fully understand.
I used to boot from an SD card too, more so because I thought it was cool (especially coming from GP2X-land) than from not wanting to wear out the NAND. Now I would only do it if the NAND really did break, or if I wanted to try Slackware and Pandebian, which I hope to get around to some day...

As far as smartphones go, they are expensive, fragile and unergonomic, can't really argue against a good rubberized case. Some even look decent :)