Which diagonal should I use?

Dear ones, I received two diagonals with my C8: a 1.25" and a 2". I have 1.25" EPs. The thought occurred that perhaps the 2" with 1.25" EP adapter might be better quality than the 1.25" diagonal.

Celestron Star Diagonal 1 1/4" #94115-A
vs
Celestron 2" XLT Schmidt-Cassegrain Diagonal #93527

I don't know much about the 1 1/4" ... will look up the model #. The 2" came in a fancy box inside of which is a luxurious looking hard case which made me think perhaps this diagonal might perform better....

Edit: I also noticed that the 2" has a threaded ring which looks like it would hold on more securely than the smooth part of the 1 1/4"

Nevermind... having compared the two the answer is clearly the 2". Even the price will tell you $34 new vs $130 new. I'm so green to all this that I didn't at first realize the 2" worked with 1.25" EPs. Now on to this polar axis finderscope business. It's already installed when I received the mount. I mucked around with the dials without realizing what it was... haven't used it yet. Is it worth aligning the axis and using this at night? I feel like I'm answering my own question as I type this.. It is probably best since my GPS and other electronics seems to fail in 10F weather.