Most people would use 1.25" eyepieces.
The 2" diagonal is handy for the occasion when one wants very wide fields of view, like with a 2" 40mm wide angle eyepiece or 2" 55mm Plossl, or a wider field of view with a 2" 30 or 32mm eyepiece than in their 1.25" counterparts.
For me, the downside of 2" diagonals is that they are a bit more unwieldy than a 1.25" diagonal - they weigh more, and one has to be a bit more extra careful when tightening them up. And most of the time I'm putting 1.25" eyepieces in them.
I have 40mm and 50mm 1.25" eyepieces which I haven't used much at all because of their narrow fields of view. Their 2" counterparts I've used only a bit more. I do now keep a 2" 40mm in my 5" Mak because I like that combination, though I wasn't fond of it in my 6" Mak or 8"SCT.
Judging from what I have, the field of view in my 1.25" 25mm wide angle eyepiece is only very slightly smaller than the field of view in my 2" 25mm wide angle eyepiece.
Anyhow - you have the flexibility with a 2" diagonal to get a few 2" eyepieces. But there is no reason to rush.
Regards,
Renato
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