The main focus of SUF is having a simplistic configuration, while maintaining flexibility that the vast majority of users care about, this prevents unnecessary bloat that sacrifices performance. While you aren't going to be able to set that you want the health bar to be exactly 3.14 pixels outside of the health bar, you can change options that you actually care about such as bar height, ordering, frame height and so on. All configuration can be done on multiple units at the same time through the global configuration, meaning if you want to set the height of Player and Target frames to 50, but then you want to set the height of Target's Target and Target's Target of Target to 30 you can easily do that with changing only two options, instead of having to do it four times for each unit.

For people who want to tweak every single setting, you can enable advanced configuration which will show extra settings for those who have to tweak every little thing they have to. However, you do not need to enable this by default, and most people should not need to enable them.

Slash commands: /shadoweduf (/suf shorthand)

Includes the general features you expect in an unit frame, like health bars, the two new ones it has are anchoring and visibility:

Modules
SUF includes basic module support, if you're interested in building a module see the documentation documentation on my github site for more information.

Currently released modules are:
Arena frames by myself
CC Timers on portraits by Proditor.
Five second rule by Kemayo
Power bar colored by class by moniker
Aura indicators for raid frames by myself
Smooth bar updates by Antiarc
Bar growth/empty bars by myself

Anchoring
For those who are driven crazy because their frames look to be half a pixel off center of your player frames, you can simply anchor the frame to the player frames and solve the hassle of aligning everything. For example, the target frames are anchored to the right of the player frame, and the ToT frames are anchored to the top of the player frames (In the screenshots).

If you tried to drag player, all the other frames will follow it in the same anchoring. Each frame can still be manually positioned and put wherever you want, but this gives you a way of easily anchoring everything and keeping frames nice and aligned without having to use a ruler.

Visibility
If when inside an arena you want to see your totot or party's target, but in a raid you don't want to see either of those then instead of having to manually change settings or swap profiles on zoning you can set SUF to do it automatically. Modules can be set to be disabled inside raid instances, but enabled inside a party instance, or a battleground.

Other features

• Tags: Includes a simple tagging system that can be customized in virtually any way using Lua, so even if something isn't included by default odds are you can make the tags.
  
• Auras: Can be set to only show auras you casted, or can cast on others. Can enlarge auras that you casted, and hide the cooldown ring on the timers of auras you didn't cast as well to make it more obvious which ones you casted and which ones you didn't.
  
• Fader: Fades frames when out of combat and inactive (100% mana/no target)
  
• Rune/totem bars: Supports simple rune and totem bars inside the players unit frames.
  
• Highlighting: Can highlight frames off of mouseover, debuffs you can cure, aggro, target and focus.
  
• Range checking: Fades frames out that are out of range of you.
  
• Exportable layouts: If you have a layout, or your friend has a layout you want to try out you can export/import SUF layouts by going to /suf -> Layout Manager
  
• Profiles: Profiles can be changed without having to do a UI reload, lets you quickly change settings based on where you are without the hassle of it either being buggy or having to reloadui each time.
  

And pretty much the usual UF features, indicators for leader/raid targets/etc, cast bars, portraits, combat text.