Nikon D90 is basically a low-end (some people think it is a mid-range) model, and its performance is close to the mid-range. It is a leader among Nikon's low-end SLR cameras (at present). If it is professional, it is probably not enough. The D300 is only a "quasi-professional model", but for general shooting needs, the D90 is still very good. If it weren't for the lack of money, I should be able to talk to the landlord more (I have been staring at it for half a year). At present, most popular SLR models are low-end models. In the low-end models, the D90 should be a good one. Of course, there is still a gap compared with the mid-range model, but the imaging is excellent, ranking 15 in the DXO mark laboratory test in France. The landlord can go and have a look if he is interested.