The one big caveat with the 1000X is that they have a possible build quality issue…so if you’re okay with living with that/taking that chance/maybe having to deal with Sony support, then they are a more fully-featured pair of headphones. It definitely doesn’t effect every pair, but it was more widespread than anyone would have liked.
I personally would still go with the 25’s, and I actually like the flexibility of the replaceable battery personally. With the 1000X and the QC35’s both having a non-replaceable battery, that basically means they’ll die permanently at some point down the road once you’ve used them for enough charges.
It’s up to you! That’s a tough call to make as both are at really good prices!