They do half sizes. I got 8.5 and I normally run in an 8. I should have got the 8 as the half size is slightly too big so have to wear 2 pairs of socks. So I would say they are true to size. Can't fault them for the price they are at the moment.
Not very heavy at all. They are not featherweight shoes but for a rugged trail shoe I did expect them to be heavier which i was pleasantly surprised about. In my trail running group about 4/5 have now got these and no one dislikes them. I don't think they will outlast the expensive well known brands but our group leader has done a good few hundred miles in his and they are still going strong.
I run with my weimeraner who is 4. He runs both off lead but I do canix with him as well. We took part in our first 10k last weekend and we loved it. Dogs make great running partners. Sometimes it's just not the same without him!