Hi Pspa123,
I don’t think one would be “better” than another although they would be slightly different. The blended is more pressure relieving and would probably be more durable in lower ILD’s (in the medium range you are looking at any difference would be small) while the 100% natural would be a little more elastic and “supportive” (gets firmer faster with deeper compression) and would be attractive to those who preferred more natural versions of latex for their own personal reasons. You can read a little more about some of the differences between blended and 100% natural Talalay in post #2 here.
I really wouldn’t treat one as being “better” than the other in terms of performance even though in the softer versions the blended would have an edge in terms of durability and has a longer track record (blended Talalay has been used and proven over many decades while the 100% natural was only introduced in 2005)
Phoenix