Having been on the pointy end of a Jabiru engine failure, having completed the Jabiru Maintenance Course and having run a flying school which used a Jabiru I have a few insights into the issue.
Firstly you need to differentiate between the 2200 & the 3300, each engine has it's own but different problems. The 2200 is mainly through bolts and the 3300 is mainly pistons/rings and especially exhaust valves. Secondly you have to differentiate geographically if the engines are run on AVGAS. The West, including SA (and maybe NT) are supplied with the Green, high lead, fuel while the East is generally supplied with the low lead blue. This has an impact on lead build-up in the engine.
Thirdly you need to differentiate on equipment level, i.e. do they have the single CHT sensor on No. 6 or are they fitted with the Dynon and have EGT/CHT on all cylinders.
With regards to maintenance it is no so much wether it was a "Professional" or an "Amateur" but more a case of how often. For example, a J230 (3300 engine, running on AVGAS Green with single CHT) has a top end clean (deposits removed, valves lapped etc) every 200 hours and hasn't had a failure in over 600 hours. This is not part of the Jabiru recommended maintenance schedule. The point being some people will go above and beyond the "required/scheduled" maintenance or strip the engine/top end at the slightest possibility of a hint of a problem. When this engine goes to TBO they say they never had a problem or failure, which is true. The other person who just does the recommended scheduled maintenance per the book, to Jabiru standards, plus any AD's etc and the engine fails at 300+ hours whilst flying therefor generating a statistic.
Most of my experience is with the 3300, and the engine will go to TBO IF you clean the top end every 200 hours, modify the baffling to get an even spread of CHT's (illegal if 24 reg) and fit fuel injection (again illegal) or possibly re-jet to run really rich (25-30 L/hour at 75% power).
As for the 2200 engines I'm not sure, but one here is only used for private flying and generally flies at 2900-3000 rpm, doesn't do circuits, is maintained above and beyond recommended levels and is running nice at 400+ hours so far.
In my case the engine was maintained to the required level as per the Jabiru Maintenance Manual, only had the single CHT and run on green AVGAS. After doing the mandatory morning pull throughs with no issues, at 282 hours about 40 minutes into a 2 hour flight the engine ran rough for 10 seconds then stopped solid, found a paddock and got down with only a few bruises. Aircraft carted off to Jabiru by the insurance company, and when we tried to find out what went wrong with the engine they wouldn't tell us! When we asked for the engine to be sent back they said they can't because it had been binned! We got a new engine (we got pro-rata for the hours remaining) and our aircraft fixed but to this day have no concrete evidence of what happened.