I got my Samsung Galaxy Note 3 in October 2013. I've never been happier with a device. My first worry was the big screen and boy oh boy, I'll never go back to a smaller screen again!
So far, the phone hasn't given me a single day's worth of trouble. And it's the perfect middle ground between phone and tablet. The 5.7" screen is big enough to actually watch stuff on, but overall the device is still small enough to function as a phone.
One thing I found myself not using that often though, is the pen. It was a very cool gadget when I got the phone, but these days I hardly take the thing out. It does come in handy when I want to use it specifically, but honestly, I wouldn't be all too sad if they dropped the pen (but then it won't be a Note anymore hey!).
In a few months I'll be able to get a new handset, and I cannot wait to see what Samsung will come up with in the Note range next. I'm very glad I got on board with the Note 3, it just felt as if the Note 4 wasn't that much of an upgrade (I'm probably wrong here).
I reckon the Note 5 will either have a WQHD screen (like the Note 4) or maybe even go beyond ludicrous and sport a 4k UHD behemoth of a screen. I really don't see the point though, my Note 3 has a regular Full HD screen, and it's gorgeous to look at, you cannot see the pixels and the colours are great, so I'm not sure if having a bigger resolution is really all that necessary...
It'll probably run a 64bit processor, which will open it up to more RAM - maybe 4GIG?
Storage will probably be around the 32gig to 128gig range, and I'm sure this one will have the whole waterproofing and dust proofing down as well.
Anyway, those are just my personal thoughts.