I’ve been using the Ordinary primers for many weeks now and I like them both for different reasons.
The High-Adherence one has a creamy texture, similar to moisturizers but with a bit of a silicony feel to it. I feels moisturizing and a bit tacky on the skin which makes a foundation grab on to the face better and it lasts longer. It does not feel oily however. It blurs the pores and evens out texture on the skin.
I think the High-Spreadability primer is even better at smoothing the skin and blurring the pores. It has a very silky texture and it glides on the skin like a dream. It makes the foundation glide on the face easily because of its smoothing effect. It has a gel like texture and feels even a bit more silicony than the High-Adherence one.
If I had to choose only one, I’d pick the High-Spreadability primer because of it’s amazing smooth texture and awesome blurring effect. I like using both though and combined they still cost less than most other primers.