I agree with the too much positive. It actually backfires, because I don't know what they are actually are doing really well, so feel I can't praise them.
I'd rather have an honest report, that I can say to them "hey, that's brilliant, your teacher says you are really trying hard in spelling." and "You need to remember to put your hand up to answer questions". That is helpful, because I am praising them for something they are doing right, and I am able to perhaps talk them through ideas to help them improve what they're not doing right.
If it's all "Spelling is very good" and "enthusiastic when answering in class I don't know whether "good" in spelling means "he's naturally a good speller", "his spelling isn't as dreadful as it was", or "he's working really hard at doing his spellings", and "he forgets to put his hand up" or "he's really enthusiastic about some of the things we're doing and is asking great questions".
We did have one teacher (all my dc have had her) who did give honest reports, and I loved them, because if she said they were great, I knew they were great, and those negatives were done in a "this is how we need to improve" way.
I think the report I was most irritated by was year 3, new school, where the new teacher had copied word for word some of the personal statement from the previous year. It wasn't stock phrases, the terminology was very much the old teacher, and the new teacher wrote totally differently. I think the new teacher thought me and dh were spectacularly stupid, as it wasn't the first time she'd done something that was so obviously wrong anyone would have spotted it. 
The other problem with positive reports, is that some people do take them at face value. I can think of a couple of people who have told me, or put on fb something that was said on the report, and I've thought, "I think they were trying to tell you a negative" but they've thought it is a real positive, and are proudly telling everyone.
I take what people are saying on position in class. I also take why they're not done anymore.
The thing about the not doing position in class, combined with the relentless positivity, is that sometimes parents have got the idea that their dc is in a class of their own at the top of the class. It comes as a shock to find (when setted or whatever) that they're actually strictly average. I have certainly had conversations where I've realised that the parent thinks their dc is pushing the top of the class/not being stretched, and I am aware from various things that they're not in the top half.
I have also had a conversation with a parent whose dc was convinced (and had told them) that they were struggling at the bottom. Parent was a little worried, more because dc was upset than they thought they should be better, but I was aware they were second group in that class.
But you can get inaccuracies from form position just as much. If I look at my secondary, there were 3 children went from my primary class to my secondary. We got put in different classes-and at the end of the irst year got form positions and we were all 4th!. But from primary, one of us was generally in the top 3, another was round about 10th, and the other was 20-25th.
When it came to setting, over half of the top set came from one class (the one with the top 3 child in), and almost none from the class which had the 20-25th child in.