Thank you all for the input. It is indeed a tricky decision to make especially as I have no previous knowledge of these machines (I am from England, UK) and everyone can really only make subjective comments, which is why I am surprised there is no universal website which offers an objective comparison of various/all units in the same manner as car magazines are apt to so do.
The various forum comments are helpful in particular regarding considerations which hadn't even crossed my mind, so whilst I set out looking for a basic mower/de-thatcher/aerator, I have quickly established the possible need for other attachments which then leads onto the ease of connection/disconnection and other things! I was absolutely convinced when I began this journey, that the John Deere X304 would be the one and then I realised there were so many others to be considered like amongst others kubota, Kioti, Steiner and latterly Ventrac 4000 but at least I am learning all the way. I would like to be reasonably savvy before entering a dealer in order that I don't come across as a complete plonker and thus an easy target to be sold something which wouldn't be right! So thank you all for input and I will return in due course to advise which I do eventually settle upon as the best of the bunch, for me.
I think your decision will be based on how your feel with your local dealers and feel of such tractor you are looking at when sitting in one. I picked kubota due to ease of features on tractor and the value of features were worth more to me on the tractor then other models features. Also the dealer attitude had alot to do with it. For example, there is a JD dealer very close to me, but didnt want to take the time to talk to me about ANYTHING related to tractors and comparisons of other brands with no backstabbing. When I went to my kubota dealer - he answered every question I had and didnt care if I asked the difference of otheer brands even if other brands was better for one or two features. THAT sealed the deal and won me as a customer for life. There is NO need to feel pressured to buy or talk negatives of any brand. I didnt buy the kubota on first visit -but went back after more research online like you are trying to do here. Feel free to ask anything here on tractors as that what we are here for.
So my suggestion - make a list of things you likee to do in your yard. visit a few local tractor dealers and ask questions and get prices, test drive a few , etc and then go home and mull over your choices.