It is a good make, the only thing I would think about is, when you have the grandchildren there isn't much space for them to play inside if the weather is bad. Depends on their age. We had a Hi Gear Hampton 4 last year which is roughly the same size as your Coleman. We would find it too small with our two grandchildren, plus table and chairs and cooking boxes etc.
We have an Outwell Parkdale 4A at the moment, admittedly an air tent, but I think the size would be better. It has the bedroom section, middle living section and a front enclosed section which can be opened out. View profile.
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets