I have never bought a share but had a look at a few (reasonably good condition IFR aircraft, in this case) and, in retrospect and sometimes a long time later, have found that each of the shares I saw were being sold in a certain amount of desperation, by pilots who saw the aircraft gradually become less and less useful (avionics such as an ADF packing up) while the rest of the group, being VFR pilots, refused to pay their share of fixing it. So this is something to consider; if you want a plane for serious going places, check out what sort of flying the rest of the group does. Phone/meet each one individually.
Ultimately, no matter how nice people appear, and indeed no matter how honest they actually are, one cannot buck their long term objectives and their [in]ability to finance them.
It's probably different and easier for basic planes which one just pops up in for a local bimble on a nice day.