@Silvarna:

A lot of people have a wrong understanding of memory usage. Even if your UI uses 30 MB of memory or even more... that's nothing! You probably have 4 GB (= 4000 MB) of RAM installed, so why concern yourself with 30 megs?

I'd like to quote Cogwheel, one of the authors of World of Warcraft Programming (First Edition):
"Unless you are an addon developer, you generally don't need to concern yourself with addon memory usage. In and of itself, memory use says absolutely nothing about how an addon impacts WoW's performance. WoW itself uses an order of magnitude or more RAM than even the most memory-intensive UIs. "

I, myself, am running with about 50 addons (yeah, I'm really an addon junkie!)
and my total memory usage is just about 30 MB. This doesn't affect performance in a noticeable way on my 3 year old PC. And why would it? Memory usage itself doesn't tell you anything about the CPU usage of your addons. What really affects performance is how much computations the addon does during runtime and consequently how much it occupies your CPU. That's what really slows down WoW. So 20 addons with 100 MB memory usage might not impact WoW's performance at all, while a single addon with 100 KB of memory usage might make your play experience highly undesirable.
Thus, I could never understand people's obesession with a low memory usage.
When it comes to troubleshooting, for me that was never really a problem. But that might depend on which addons you use together and on the quality of the addons.
Sorry for the rather longish and fervid comment, but I really felt the need to communicate this :)

@Emandiputs:
I'm not using Raven myself, but you would just have to scale down the buff icons and tell Raven to only display 5 buttons per row to achieve something very similar to Aeide's setup.