We've moved several times with packers. The last few moves have been with Eurogroup, Whites, Brittany and Fox. Euro group and Whites were amazing although they were all good.
They generally have similar rules.
They will all pack but they pack what they see. They don't sort it out. They don't find the right shoe to go with the left or empty the waste paper basket before packing. It is up to you to deck utter and be organised as in having everything where you want it/should be before they arrive to pack.
They usually ask for furniture that comes apart to be dismantled before they arrive. Things like bed frames. We usually dismantle a day or 2 before and just sleep on our mattresses on the floor. It saves a lot if stress as they do tend to arrive first thing in the morning on packing day.
They do pack garden stuff and more often than not shed garage and garden stuff is last on the lorry. Again you need to dismantle swings benches etc. They will discuss with you at your premise survey details about any plants they will move for you. Sometimes this is an extra cost. They won't move petrol nor empty petrol mowers, chemicals like weedkiller etc, paint and varnishes, car oil etc. So you need to consider getting these moved yourself.
I love the packing service. They pack so fast and better than most normal people would. Also in most cases your insurance is only valid if you have used professional packers but read your own small print.
Hope thus helps.