In reply to Rob Stratton:
I've had SLs for a long time including the latest model. Since I've had heel blister problems in the past as well as wearing the lining at the heel on (only) one older SL model, I've been using Engo patches on all my 3-4 season boots ever since ( about 7 years now). I put them by default in the SL activ boots when new so can't say it they would have worn away at the heel since the patches definitely stop that.
Still think the SLs are a good choice of boot for me, but then again I've not tried out some of the newer makes or models - usual if it suits why change it.
If you really want SLs and avoid potential heel lining wear if this is a problem I would definitely recommend the Engo patches.
http://www.goengo.co.uk/product/heel-patch-pack-2-heel-patches/ . I even used them on the older boots that did have worn lining after it was damaged and the boots lasted another two years of use before I finally binned them - the new model is a lot more comfortable and tempted me
.
Not cheap but I find the patches last much longer than they say. I get more than a year out of each patch, prob around 500 miles, if careful how you put the boot on. On the other hand if you say just slid the heel down heavily on the heel of the boot you can have the patch ****** after one or two uses!! Slacking off the boot or using a shoe horn and as I say they last well over a year for me.
Hope that helps you decide.