I love the Ampex ATR 102. As a young recording engineer, this unit was the most popular two-track throughout the industry.

The Studer A820 was the big dog on the block, but the 102 was ubiquitous. It was in practically every studio in LA. If you hit the tape right as a mixdown device, the compression was a combination of warmth and smack but still transparent.

It added a particular color to the material, but at the same time, it didn't. I know this is contradictory, but that was my experience.

Other uses for the machine were to "fly-in" tracks (look it up) and also create "tape loops." Fyi this is where the modern use of digital loops originated. Look that up, too.

The 102 also had another use that was brought back to memory after watching this video by UAD and Vance Powell. That's using it as a "slapback/tape delay." 

By the time I entered the industry, digital delays were already in heavy use, and tape delay was only used if you ran out of a piece of delay outboard gear. It was still utilized, though, and Vance explains how it's done with the UAD Ampex ATR 102 plug-in here on the UAD website.

Enjoy!