How is it possible to replace TRIM at the hardware level? I wasn't aware there was any way for the drive to know what files the filesystem considers deleted. Unless the hardware module somehow detects what file system you're using...
Hardware GC is useful and decreases write-amplification problems, but it doesn't remove the need for TRIM (which affects wear leveling and physical fragmentation).
Sandforce and Samsung SSD chipsets have native GC built-in.
All that TRIM would do is improve write performance (so it doesn't block at random for GC) and allow for non-OEM SSDs.