Pentax XL vs Nagler type 6 for daytime use

I'm seeking advice on the "comfort" factor of using either Pentax XL or Nagler type 6 eyepieces for daytime birding. Should I be concerned about a difference between these two eyepiece types relative to eye placement sensitivity, kindey beaning and blackout?

The specific eyepieces I'm considering are the Pentax SMC XL 14 and the Nagler 13 type 6 (and maybe even the Nagler 12 type 2). The scope is the Takahashi Sky 90 (fl = 500 mm).

My desire would be to go with the smaller Nagler type 6 with its wider field and adequate eye relief (12 mm). I would be willing to modify the eyecup with a set screw to keep it from moving if I find that desirable. My hang-up is, when viewing comfort is mentioned (which I believe will be an extremely important consideration), the Pentax is the one to receive almost universal praise.

I also realize that I may have to buy both used, do my comparison testing, and end up selling one of them. I'd simply like your experienced opinion before doing this.

(To further complicate this, I'll eventually need to make this same decision between the Pentax XL 5.2 and the Nagler 5 type 6.)

Thanks all.

Tim

There is no sliding eyecup on the 13N t6. I use the 13 N t6 in both a 92.5mm f/4.9 apo and a 105mm f/5.8 apo for birding and it is a pleasure to use. No daytime experience with the Pentax, so can't help with a comparison.

Paul

In my original question posted above, I mentioned that a Nagler 12 type 2 was a consideration. I meant to say a Nagler 12 type 4 was being considered.