GUI is smooth and very easy to work to develop the required circuit. It is all supported feature-rich and gives support while development. Component level searching and layered development are user-friendly. Some options are very good to have while working like Auto zooming, traces on inner layers, horizontal flipping, Design Rule Check, Silkscreen on the bottom layer, Expanded Undo Function, Allow copy and paste between multiple instances of the application, Component Builder, Advanced Component Search, Shift key to constrain horizontal or vertical movement, Auto number reference designator, Auto-zoom and centre netlist error, Ability to connect via to more than one inner layer for multiple ground planes, Highlight wires and pins in a layout that are connected, Design Notes, Visual Board Revision Comparison, Enhanced Solder Mask Editing, Visual Design Gallery with Search and Filter, Enhance Part editing and grouping, Bill of Materials, Enhanced Printing Functionality, Streamlined PCB Ordering Process, Expanded Hole Sizes etc...

Its awesome. Since 2005 I am using it for the PCB designing. I love its size, portability and simplicity. Best part is, its free.

Actually i use this softer for tracking line & I used it for optimizations of the circuit.