Cheapies? I've used a couple, usually when helping others set up their own editing station.
- Scarlett 2i2: the control panel can sometimes stop "talking" to Pro Tools, resulting in dialogs about being unable to change sample rate. Otherwise, it's fine.
- Phonic Firefly302+: Persistent whine in the headphone amp (does not affect other signals). Otherwise it's fine, but I don't trust Phonic to keep a tight driver release schedule.
- MBOX3: Gain jumps exponentially at the last 1/10th of the dial. Otherwise Great.
- Firewire 410: Had a few issues with drivers on a mac, no issues at all with PC. Low latency, excellent bang for the buck.