Okavango there is usually a peak in hours.
Before say 150hours your finding your feet but you are keen as hell. Then up to about 700-800 you know what your doing and are still enjoying it. After that there tends to be a drop off as its become a job and if your instructing properly you are giving a bit of yourself to every student and after about 900 your getting a bit fed up and need to move on either up the instructor ladder or off to airlines.
The keen nature of the guys that are restricted more than makes up for the lack of experience as long as they are in a healthy school environment where its normal for them to be supported by the more experienced FI's. These guys will be more likely to give full briefings and go the extra mile with you. The over 900 hour guys are bored and can't be arsed in general. So there is a sweet spot in the middle but very experienced can have its problems as well. Normally the ultra keen restricted instructor will be more fun and that will make up for the lack of experience.
And if there is a real problem you will get handed off to a more experienced instructor and then given back and if its a good school the restricted instructor will be sitting in on the briefings/debriefings that the experienced instructor gives. This handoff though is extremely rare in my experience. The times it has been happened there has been something which takes a bit of mind games to sort out which some experienced instructors struggle to deal with never mind sub 100 hour instructors.
And I would agree about the way it works, some instructors cards are marked for good or bad within days of them starting at a club. Sometimes it seems they are the last to know they are starting a type rating in a couple of weeks. And others everyone knows they have no chance and its a bit embarrassing hearing them mouth off that they only have xxx numbers of hours to go before they are off. Then they are bypassed and they turn bitter and to be honest its in everyone's best interest they take a break from either the area or from instructing.