Undeveloped is VERY impressive, I might be moving back to them soon. The look is great but I had less offers & sales when compared to less modern looking templates --- that's a (huge) factor that should also be considered.
Flippa, Sedo, Undeveloped regarding offers/sales.
Undeveloped, Flippa, Sedo regarding visuals and templates.
What I think efty is far better as their landing page is of quality.I will try undevloped also.As suggested by Loredan I may redirect my domains to my website flippdomain.com.