Before we get carried away with stories of 'weak' aircraft and the like, poor southerners post doesn't give any details about the conditions under which the Arrow 2 lost a wing. Any aircraft can shed bits if you find yourself sufficiently outside the envelope. Of the three Mooneys lost by a local flying club over the past 20 years, one was due to an inflight break-up.
As with most things conected with aircraft, the answers you get depend on who you ask. All aircraft (well most anyway) have a certain number of ardent followers. What you plump for in the end depends on what you want to use the aircraft for. As sternone says, the Arrow and the Mooney are in different classes.
I've found the Turbo Arrow IV a fantastic aircraft for long distance touring. Wide, cabin with plenty of space. 5 hours endurance with reserve and good load carrying capacity. As stated the downside with the IV is its' love of tarmac (or grass) but if you're angling for a III then that should be less of an issue.
By comparison I've found the Mooney, while light and a delight to handle, just doesn't fit. I'm not tall (5'8") but I still find it cramped and the relatively low seating position less than ideal. The other achilles heel seems to be a tendency toward prop strikes.
As I say, ask a simple question and you'll get a thousand different answers. Stand-by for a stout defence of Mr. Mooney's finest from the guys who fly and love it. The ramblings above are my experiences on both types and although the Arrow IV is heavy in pitch and uses up ground getting to 75 knots, I've enjoyed every minute I've logged in them thus far.