I have been a member of GR for a long time and have made many useful connections. However, I would advise anyone not to use GR for their main family tree, it is more advisable to have a dedicated programme on your own PC and use GR as a supliment.
I have a very large tree on my computer, only a fraction of which is on GR, also the information I keep on my GR tree is very basic, just names, year and Towns of BDMs, this is sufficient for others doing a name search to decide if they think we may have a link.
Sadly, there are some people who expect to have everything handed to them on a plate, or they will incorporate your whole tree into their own, regardless of whether they are genuinely connected, and others who will take what you have to offer without sharing their own information
I am happy to open the tree to anyone who appears to have a proven connection, then once we have exchanged basic deatails, I prefer to correspond with them direct and will happily pass on full details of the branch through which we are connected, including certificates, wills and other documentation and sources. This ensures only genuine researchers get the the benefit of my years of research and expenditure, I would still expect them to do there own checks on whatever I have passed on as I do don't claim to be infallible.
Jebber