Plenty of mixed experiences with retail tastings, but that's like wine in general, mixed experiences at all price levels! It all adds to the learning experience and the good ones make up for the average ones (I'm too positive to call them bad).
Offlines on the other hand are always excellent, mainly because you're part of a small, like-minded group of people/friends, but also because the styles and age range are so much more varied (well IME anyway). I almost never see any aged examples of wine at retail tastings, and when I do, they're not usually aged enough. Hard to complain though when the cost/wines-on-offer ratio is often very good, but I've been to a bunch of tastings where there may be 400 wines on offer, but only 5-10 I would actually consider buying. Easy to be fussy in the face of so many wines though! Of course showing aged wines is not what retail is focused on, it's about selling the new stuff so you can drink or age it yourself.
Went to the TWE tasting here in Sydney last night, some very nice wines, plenty of OK stuff and a few disappointments, mainly when I see the price of something I like! As dave vino mentioned recently, $40 is the new $30, or as often seems the case, $120 is the new $70. Highlights for me were the Wynns John Riddoch 2012 and Messenger 2010, along with the Seppelt Drumborg Riesling 2015. Quite liked some of the Leo Buring's too (Leonay 14 was a bit shy though, but texture was great), their Clare Dry 2015 was rather nice for under $20 too I thought. Other decent wines for my taste included the Seppelt St Peters Shiraz 12 and Seppelt Sparkling Shiraz 04 (under crown seal) and yes the Grange 2010 was pretty lip smacking tasty too, if you can afford it!
Cheers
Tim