SCID vs Arena

So far I have used Arena to manage my game database, but now I am starting to check out SCID.
I really like the way you can have Arena show its calculation with arrows on the board while you inter the moves from OTB play. Has anyone got experience with SCID and has recommendations?

Both Scid and Arena are great options. I personally prefer Scid for storing large game databases, in Arena I think it's a bit more difficult.

I've been using SCID ( SCID VS PC) for years. Tried Arena once and found it confusing. SCID just works for me and GUI layout is intuitive. Try both and use what works for you.

Arena looks simpler, SCID demands some exploration, particularly menus and I do not understand why they make it so hard to delete game from database. 

However both are good tools. Arena was not updated for last 5 years. 

It's been eight years since the original question, so I guess the guy decided on his GUI(s) long ago. Assuming the OP's profile is up to date, it looks like he settled on Arena and Tarrasch Chess GUI.

Arena is good for engine tournaments and playing against engines; Scid and Scid vs. PC are good for databases, especially large ones. Arena's database features are very basic, but probably okay for small, personal databases. (I seem to remember that if a database gets into the area of millions of games, Arena gets to the point where it can't handle the size of the database.)

I'm not sure what that means. Are you talking CPU usage or RAM usage, or both?

I never really paid attention to Arena's RAM usage, as it never seemed to be a problem for me. (And my PC only has 8 GB of RAM.)

Regarding CPU usage, the GUI usually uses a negligible amount of the CPU resources compared to the operating engines. The CPU usage is more a factor of how many threads the engine is using, compared to how many threads your CPU has available. In Arena, you can adjust the number of threads that an engine uses.

I've never used Arena. Why is it good for playing against engines? Is it good for playing against various engines at dumbed-down Elo levels?

Arena is good for playing against engines for a few reasons. You can install nearly any Winboard or UCI engine, and there are many game-related settings available. The downside is that there's a learning curve for all of those settings. Another reason, which is solely "eye-candy", is that you can install logos for the engines. :-)

Regarding dumbed-down Elo levels, Arena can handle that, *IF* the engine has that feature. Most of the preinstalled Arena engines don't have that feature, so you'd have to know which engines to install to get that capability. (You can dumb down any engine directly from the GUI by limiting nodes, search time, or search depth, but that's not an ideal way of doing it - better to have the engine control the "dumbing down" process.)

If you want to use dumbed-down engines but don't want to mess with engine installation and configuration, then you're probably better off just using Lucas Chess.

I have been using Arena mostly for daily PGN works. No use for playing against nowdays engine, hence for this purpose i use still chessmaster, or android shredder, droidfish apps

from my side; i like it's simple  GUI design, it is generally easy to use, easy to install, easy to adjust.  I hope that developer will continue with Arena project, even recently there was update for linux OS.