KWC... this may be of interest to you, I think it is the most object review and comparison in the press:
http://www.ridermagazine.com/road-tests/adventure-shootout-bmw-r-1200-gs-adventure-ktm-1190-adventure-yamaha-super-tenere-es.htm/
A similar thread is currently running on ADVrider. Several of the GS/GSA owners active in that thread were former ST owners, some were ardent supporters of the ST before they made the switch:
http://advrider.com/index.php?threads/pre-2014-super-tenere-gs-lc.1103258/
You requested we share our personal experience with BMW's, here's mine. Hope it helps.
My personal experience with BMW:
Me: I've got 55+ years of riding experience, have owned more then 50 different bikes, during most of my life bike were my primary mode of transportation, Now that I'm retired I ride 20-15K miles a year, about 5K of that is in Europe. I keep a bike in Europe and spend 6-8 weeks each summer riding there. I'm a lucky guy living my dream, life is good! I'm no fan boy of any particular marques and will own/ride anything that makes me smile. I've been stranded at roadside twice on a bike one was on my '09 Moto Guzzi 1200 Sport with electrical issues, and the other time was on a '06 FJR with ignition switch issues. I was travelling on the FJR and was stranded for 5 days 800 miles from home, it was a design issue resulting in many failures and no spare switched were available in the US. The dick head Yamaha dealer would not swap a switch from a new bike he had on the floor until I made legal threats to Yamaha customer service. A month later I received a recall notice from Yamaha for the ignition switch. I was reimbursed by Yamaha Corp for parts and labor but not for the 5 days lodging or food (I was just a few days out of the warranty period)
My 1st BMW was a new 1973 50/5(32hp/425lbs naked) with a Vetter fairing and Krauser panniers, a proper touring machine in its day. Since them I've own 7 other BMW's( 3 boxers, a flying brick, 2 parallel twins, and a 6 cylinder) have put maybe 250,000-300,000 mile on them and never had a major issue, have never been stranded, no hard stars issues, no fires, no CTC failures, no wheel/spoke failures (BMW tubeless spoke wheels are know to be the best in the business) as reported here on this forum. I have had recalls from most manufactures so BMW is not alone in that regard.
You can see from my experience that it has been Yamaha reliability and dealer support that had the a more negative impact on my riding experience then BMW.
BNW did have some rough years from about '04-'08 and were slow to respond to issues and sometimes in denial. Dealer were pissed and customers less then satisfied. That's changed. They are more customer friendly, more responsive to issues, work more closely with the dealer network, and most importantly have designed the completely new LC line with focus on reliability. Major improvements were made to the clutch, the final drive, and of course the motor. As I see it, the LC GS/GSA are a much better package then earlier models and at least on par with Yamaha for reliability, and in my part of the world BMW has a much stronger dealer network.
Hope you find my experience helpful in your decision process.
Just yesterday I was at my local BMW/Duc/KTM dealer to pick up the parts I need for a service and I made a big mistake, I took a test ride on a 1290 Super Duke they have as a demo. Sooo light weight, great motor, excellent suspension, surprisingly comfy, quick handling but stable at speed..... if only I had the room in my garage for one more. ::025::
Paul