I used 3 of these - one personally and two on a BBS - and they were legit. They were just absolute workhorses, and they really were software upgradable to whatever was happening in the industry. My school acquired two via an educational BBS program and they were the only two modems the program ever bought.

At home I started with a Boca 14.4, and upgraded to a US Robotics Sportster 33.6. I got the Sportster early and the modem ended up having a "death spiral" issue where speeds would decrease over the length of a call. Thankfully USR socketed the ROM in the modem so you could login to their BBS, request the new ROM and then replace the ROM to resolve the issue.

After going through the ROM ordeal, and then seeing 56k fracture into two incompatible camps initially (X2 and K56Flex), I really wanted to get into a Courier at home to avoid a likely double hardware upgrade. I eventually got into a US Robotics discount program and was able to make it happen by flipping the Sportster. I ran that modem to the end, and sure enough when 56k was standardized into V.90 it was a simple software update on the device.