Just picking up on this thread, I thought I would put my tuppence worth in as a shareholder and company secretary of an Arrow group down at Bournemouth. I bought my share many moons ago soon after getting my PPL with intentions very similar to yours. 17 years on Im the longest serving group member and deal with the day to day running of the group.
This is the way I see it;
1) Its unlikely you will fly as much as you expect too (although you are far more likely to achieve your hours in a flexible group than by hiring)
2) Any group ownership generally involves a commitment to stump up cash in the event of expensive repairs - of which there are many potentials (in my time weve had a new engine (£15k 15 years ago), new wing spars (just dont ask!!!) and top end engine O/H at 10k, all over and above the standard 3k annuals and £800 50hr inspections. These can be offset by a healthy fund, but generally this is for the 2000hr engine o/h fund, so if the gods conspire to hit you with expensive repairs at the wrong time then there is always the possibility of a 'pocket dip'.
3) As genghis says usually when you buy a share you own either an xth of the aircraft or as we do own a share in the company that operates the aircraft. Therefore selling on is usually subject to free market conditions and you get what you can for it. Its usual to allow any new member to be vetted by the existing group although this can be a problem if the group dont agree with the new encumbent. All manner of poo can transpire in those situations!!
4) Unless you fly enough hours then renting will always be cheaper - I dont fly enough and if I consider the money I have put through the company coffers then I could have done all my flying in a Baron and still be better off!!
5) However, whilst the last 4 points have sort of been a bit negative about share ownership, there is the one huge benefit ownership which you have mentioned but for me is the key to what makes it worthwhile :- and thats the ability to pop the plane over the channel for the weekend without having to worry about getting it back for the next renter. The ability to leave the plane at a relatively close field for hours /days etc without having to worry about minimum daily flying hours or getting it back cannot be under-estimated in my mind.
I don't begrudge one bit being in a syndicate but just be sure its a friendly group, with good availability and decent fund reserves and you will find the freedom of booking an entire day to pop over to Bembridge for example a breath of fresh air against normal club aircraft.
Anyway either way good luck with the forthcoming PPL - as an aside we may have a lovely share available in EGHH
Regards N