apexcell - thank you for all the info, I found it to be helpful and quite informative.
I mostly use my microSDXC Samsung card for storing music, video and photo files. Since my LG G3 has 32GB of ROM (24.70GB available), I didn't choose the option of installing apps to the external SD card. However I did put my system backup on there. I have 55 apps installed and still have 20.51GB of ROM to use of the 24.70 freely available on the internal ROM. I believe that will be good enough.
I am definitely not an Android uber geek to say the least!

I am learning though. I've only had Android smartphones for about 2 years.
Started out with a Chinese brand: STAR N9500, then had a Chinese Lenovo K860i for a few months, then bought a Chinese Zopo ZP998 which I liked but then AT&T changed some of their 3G frequencies which caused me to lose the 3G service. ( I live in Austin TX, it was an interesting fact that when I went to the US East Coast last October once I left the Austin metro area my 3G connection was working again. So it must have been only in Austin TX and also the Dallas TX metro area which I went through on the way back.) At first, last August when the 3G went down in Austin I thought it was a hardware issue with the phone itself. These issues occurred with Straight Talk first, then I switched to Cricket... same issues. A couple of weeks ago I found an excellent buy on Ebay for an LG G3 D850 phone for $340. It was listed as being in "pristine" condition and it was! Looked like it had never even been unboxed, no scratches, dents, dings, scuffs, etc. So I was a very happy camper! I now have a 4G LTE connection through Cricket. I was able to sell the previous phones on Ebay for rather decent prices.
I like the XDA website because I am able to learn a lot about the Android OS, and pick up tips, tricks and other useful info.
Time to step down from the proverbial podium...
Nibiru2012
---------- Post added at 08:52 AM ---------- Previous post was at 08:44 AM ----------
anyone try toshiba TR card ? is it good for G3 ?
After checking out it's specs seems like a good card. I'm sure you meant a TF card...
Here's a link to StorageReview dot com to read their review on a Class 10 64GB card:
http://www.storagereview.com/toshiba_microsd_class_10_uhsi_review
Should work alright with the LG G3.