I've had Elite Plus for 3 years now and it never got me anything. Lounges are all the same, as TK does not have First Class lounges. And as said before, you can't enter the First Class lounges of other *A members.
During all those years as Elite Plus, I never got any status upgrades and never any special recognition.
1) When I was delayed in IST for 6:05 hrs on my way to HKG and sent in a complaint, they told me that it was an "operational issue" and that they were free to determine whether or not to compensate. They sure are, but I would have expected a little more towards their highest status level pax...
2) Not ONCE since I've been Elite and Elite Plus did I actually get a seat when I was waitlisted, even booking weeks in advance and waiting it out for several more weeks.
Granted, these are my personal (unfortunate) experiences. Now for something more substantial:
As far as I know, the only difference to Elite is
- You can gift an Elite status to a friend for 40K (should that be relevant to you)
- You get 2 free upgrade coupons per year. Thing is, there is hardly ever any available award space - I threw my last one out on a connecting flight MUC-IST....my last flight with TK.
Summing up: Elite is nice cause it's *A Gold. Elite Plus is entirely useless. OW Sapphire/Emerald are hugely superior (I say that only having ever made Sapphire, but was fortunate enough to accompany Emeralds on multiple occasions).