I built both Italeri YF-22 and YF-23 in 1/72 scale. The fit is poor, as usual per Italeri, gear doors are too small and there are large gaps as with the weapons bay doors. If you put the gear down and open the weapons bays they can be fine kits. If you build gear up, you will need to do a lot of filling. The level of detail is minimal, as usual in Italeri 1/72 kits or Italeri kits in general, but it leaves lots of room for improvement. On the YF-23 you will need to fill a large seam between the upper and lower wing halves. The lower wing surface fits inside the upper wing so there is no seam in the leading or trailing edge just a large one under the wing, around the perimiter.
Italeri also makes a YF-22 in 1/48, I have the kit but haven't built it yet so I can't tell you what it is like. But the detail looks sparse.
The only 1/48 YF-23 kit I know of is the Collectaire resin kit. It is very pricey but looks to be a very nice kit. You can find it a www.collectaire.com
The Italeri 1/72 kits leave a lot to be desired but still look very nice with the right amount of work when finished.