I have 3 SBR uppers, one needs to go to pay for a new toy.  If you owned all three, which would you sell?

14.5” is too close to 16”. Keep the truly short uppers.

ETA: I have 10.5”, 11.5” and 14.5” 5.56/223 uppers, a 10.5” 300BLK  upper and an 11.5” 6.8 upper.

I like the 14.5”, but it just isn’t enough advantage over a 16” carbine to be worth keeping.

I’d sell the one I shot the least, the least accurate or most used up, or the one easiest to replace if I got sellers remorse.  Just based on your descriptions I’d unload the 10.3 because a 12.5 is a better compromise in 5.56.  

Since you want to fund new toy(s), another way to look at it is strictly economics and profit margin. Look at your cost basis on each versus current market comps.  Sell the one with the most gain.

I didn’t vote in the poll, but if I did I’d dump the 10.3.

I'd take the RAS off the 14.5 and part it out. Depending on what you have you can get a decent amount for it. If that's not enough, then yeah, the whole 14.5 is what I'd get rid of.

Voted 14.5. If it was a midlength then I would have picked the BCM but 14.5 carbine…so 2005. Get rid of it and enjoy more modern uppers like the other 2.