The feature comparison of Starlink vs Viasat for passenger aircraft service is:

Bandwidth Speed

Viasat:

Viasat's latest generation (ViaSat-3) offers speeds up to 100+ Mbps per aircraft
Previous generations typically provided 12-30 Mbps per aircraft

Starlink:

Starlink promises download speeds of 40-220 Mbps per terminal

Upload speeds of 8-25 Mbps per terminal
Starlink appears to offer potentially higher peak speeds, though real-world performance may vary.

Key Features
Viasat:

Global coverage with geostationary satellites
Established provider with long-standing airline partnerships
Offers streaming capabilities for video and audio

Starlink:

Low Earth orbit (LEO) satellite constellation for lower latency
Gate-to-gate connectivity (usable during all phases of flight)

Promises to enable live TV, gaming, and video calls
Free service for passengers on airlines like United.