I haven’t noticed a difference in the quality of the grain and honestly I don’t pay much attention to it. If I am shooting 800 in an old camera, I will usually put an ND filter on to give more head room. It requires a bit of figuring for correct exposure, but not a biggie. For a good inexpensive MF camera, the Yashica 124G is excellent. The Minolta Autocord is superb, but its focusing lever is cast aluminum and prone to snapping off - this happened to me. There is a gentleman who specializes in repairing the Autocord in the US for very reasonable cost - he replaced the broken lever and restored the camera to like new condition - I think the total cost of repair was $200. The build quality of the Autocord is (the lever aside) better than the Yashica - the Yashica feels sort of tinny (superb lens) and the Autocord is like a swiss watch. The Autocord lens is the equal of any other TLR lens, bar none. I find that TriX is especially beautiful in medium format.
A great inexpensive system for MF is the Pentax 645 (first model). The N and Nii versions came with bells and whistles, but the first one is fine. The Takumar lenses are absolutely superb. I don’t own a 645 but I have a 67 (incredible image quality but a very heavy camera) and a Spotmatic. My friend Kelly Shane Fuller has a Spotmatic tatooed on his arm! Google Kelly, he is a hoot and very talented. He is a fellow member of the Film Shooters Collective. You should enter some of your imagery into our periodic “journal” calls for entry. It is quite a thrill to have one’s image picked out of the many submitted from around the world. What people can accomplish with a camera in the hand never ceases to amaze me.