C# - WinForms - SDI or MDI Approach? -

i creating visual c# winforms application contain 4 forms:

1. a "control" form have anywhere between 2 buttons , potentially 10 or so. screen need accommodate enough space maximum amount of buttons.
2. a "logging" form contain large rich textbox control.
3. a "config" form contain tab control various configuration settings can tweaked.
4. a "order log" form that's similar #2.

it's user want reposition each of these forms in different ways. yet, these forms "managed" parent form when application closes, of other forms close. there way keep mdi approach, yet allow child forms move outside of parent form using c# winforms? thanks!

i have worked mdi applications bit , have tried similar.

there few things have learned experience should consider before decide.

one thing have noticed mdi's forms , controls seem paint little slower regular forms. when click link/button , throw new child form, can see visually paint new child form onto screen, makes application seem sluggish. has been tested on huge host of hardware/os combinations , test applications aren't doing opening form controls on it.

another thing mdi child windows contained within parent window, works applications, annoying others.

another quirk mdi cannot use window transparency, if have such need that.