graphic_eqPreamp and sound qualityNotableexpand_more0 mentions
Long-term owners describe the built-in preamps as excellent, clean, and naturally warm rather than synthetically harsh. Ribbon mics on amps and drums are said to get sufficient gain, and the overall sound was called a major upgrade over older soundcards.
Strongly positive
cableI/O flexibility and expandabilityNotableexpand_more0 mentions
Users value the large channel count, ADAT expansion, and ability to link multiple units for more inputs. The firmware update enabling up to 16 ADAT channels at 48kHz further extended expansion options.
Widely praised
attach_moneyValue for moneyexpand_more0 mentions
Several buyers picked the 18i20 for its price-to-I/O ratio versus competitors, noting a big quality jump for a reasonable cost and citing it as a deciding factor over pricier alternatives.
Widely praised
power_settings_newPhysical power switch (4th Gen)expand_more0 mentions
Multiple 4th Gen buyers specifically praised the addition of a real power switch, a feature they feel is missing from too many modern devices.
Widely praised
surround_soundWindows driver/surround supportexpand_more0 mentions
One long-term Windows user highlighted that the 3rd Gen's WDM drivers enabled 5.1/7.1 surround playback for games and movies, something even a pricier Antelope interface couldn't do.
Widely praised
headsetDual headphone outputsexpand_more0 mentions
A user cited the two independently controllable headphone jacks as a specific purchase driver, useful for tracking multiple performers.
Widely praised