I play 900 Tours (forged) they have more loft and a smaller head than the 900 forged never really like the feel of the latter in comparison but the heads would be better suited to a someone looking for more forgiveness in the head. Two mates who had the latter but they were not in their bags for long but they change clubs a lot more frequently than me.
Sorry saw you got to 900, neighbours son has jpx 850, he is down to singles now and was complaining that the 7 iron goes 195 yards. They felt very head heavy but that might be his set up. Very forgiving and strong lofts .. they served him well, so probably good for 10-16 handicap. Well worth a look, eBay will be around £300 for pristine, but need to be careful on your shafts.
Tried the 919 range. The forged are very nice, powerful and forgiving, bit complex to my eye. The tour, is smaller, and sublime, but you might get a bit scared by the 5 and 6 irons. When I was knocking the 7 iron out, I was surprised at how forgiving they were. So then I tried the mp20s and ended up with a blended set with 5 and 6 in hmb, with 6 iron weakened off by a degree. Absolutely love them.
I have 850 forged and 919 tour. Gamed the 850’s from around a 14 HC but got the 919 last year when I hit 11. The biggest problem I have with the 850’s is when you thin one (my poor Shot tendency) the ball goes miles and generally got me into a lot of trouble. Thin the 919’s and generally they’re 10 yards shorter - unless carrying water Id rather be short every day of the week!
I switch back to the 850’s from time to time and after a few holes I’m wishing I’d just stuck to the 919’s
Mizuno don't make bad irons so I would think any of those models would work. The more bladed the club though for a mid-handicapper I'd suggest the less forgiving they would be so strike may be an issue