blikseme300,
No, SIG has NOT discontinued our large Sundancer ARF. No reason to, it continues to sell well and customers still enjoy this model. I've been flying mine for the last four years or so with an F.P.E. 4.2 gas engine and it continues to deliver a great deal of enjoyment for me. I fly it hard and it has held up beautifully. Weak wing(s)? I don't think so. That said, is the Sundancer the best choice for a glider tug? Maybe - depends on who's flying it, I suppose - but my first choice would be something like the Rascal 110. The 110 has been a highly successful glider tug over in Europe for some time now and is capable of hauling up some seriously large sailplanes. The Rascal has a much longer tail moment and a more favorable aspect ratio, making it a lot more docile in the tug role, when properly powered for the task.

Merry Christmas from SIG!
Scott Christensen
SIG Mfg. Co., Inc.