This topic has been brought up before in the past, and there has been fixes for high RAM usage in the past. I'm just saying that possibly due to the nature of how Adguard's developed, the programming language it's developed in and how web browsers are trending to use more resources as time passes, it *may* be as good as it gets. For example .NET applications (coded in C#/VB.NET/etc.) are well known to use more resources too. Also if you visit a lot of 'heavy' websites that contains a bunch of Flash videos for example, Adguard is going to need access to more resources so it can properly process all that data, such as elements, applets, etc. We'll have to see what avatar has to say about this and whether or not there's still any room for memory optimization in this regard (or some sort of garbage collection to regain more RAM after processing heavy amounts of data).
My personal opinion on this is; higher capacity RAM's getting cheaper these days. Most computers come with at least 4GB of RAM now thus making resource usage numbers less relevant like it would of been 5+ years ago during the XP days.