I’ve been an owner with AirShares since 2007 after 26 years as sole owner of an Arrow. I’ve been very happy with the program and found excellent availability, well kept aircraft (in fact I have my own parking checklist just to make sure that I leave everything just right), quick attention to squawks (and no concerns about how much it might cost), and easy scheduling away from home base when needed- e.g., sightseeing flight over NYC with no need for additional checkout- avionics were identical.
Tips- they do let you carry over some of any unused hours per year, and, unfortunately, they do have an extra fee if you use some of the extra instruction time that they provide. You can have all of the instruction that you want without the extra fee if it is within your annual flying fraction.
They do have some regular mandatory training but I’m always a fan of this anyway and it only makes us all safer. The AirShares instructor I’ve used has been first rate.