Almonds are the best source of vitamin E, calcium, saturated oil and more nutrients and Walnuts are a good source of Omega 3 and many other nutrients. Both nuts play different roles in our body. A very few vegetarian foods have omega3 fatty acid, as I know other food name is Alsi. Simply here we are talking about the nuts so Both the nut are very useful for our wellness.
Yes, you are right that nuts are useful for our heart. Almonds doing a protective work against cardiovascular disease, maintain b.p. and control blood sugar as well. In the same way walnuts give same, but more than almonds to the heart like to maintain b.p and cholesterol level and improve cardiovascular activities. Both are the Antioxidant food.
Now your other problem that which form is more better to digest easily. So the roasted nuts can easily digest to compare its raw form, yes, we can eat both the forms because we chew nuts in a good way, but kids do not. So powdered form is better for children. Now we put more efforts so the water soaking nuts are to be digestible and have more nutrient for all ages of people. But in a high quantity of nuts can be harmful because almonds and walnuts high calories. So we need to take it in a low proportion according to our age.