A 5:1 reel has a useful mechanical advantage for deep cranking and high resistance lures. Outside of that it’s totally personal preference. Neither of the choices you posted are limiting or adding what you can do with it. Go with your gut. 

I have the 8.1 and 6.3.  Get the 6.3.

 

The 8.1 is pretty darn fast. Rated at 33.9" per crank. The 6.3 is 26.3" per crank.  More well rounded. 

@Ravox I have zero issues fishing a t-rig (or jig) with a 6 speed reel. In fact, I can only recall ever missing 1 fish that ran at me so fast I couldn't catch up and set the hook. She was a big girl who smashed a frog and sprinted straight at me and under the boat... I was using a 8.1.1 reel and couldn't catch up to her. 

 

 

2 hours ago, Lead Head said:

@Ravox I have zero issues fishing a t-rig (or jig) with a 6 speed reel. In fact, I can only recall ever missing 1 fish that ran at me so fast I couldn't catch up and set the hook. She was a big girl who smashed a frog and sprinted straight at me and under the boat... I was using a 8.1.1 reel and couldn't catch up to her. 

 

 

That is the answer I wanted, decided and got the 6.3  sounds very balanced for all the applications i want