i never found a good use for gkrellm or conky (both look ok to me, slightly leet, but in the end i never know what to do with them)
During antiX live sessions, the conky line conditionally displayed (or absent) stating "Root Persistence Enabled" is a
good use, IMO, also the line indicating free space available. Historically, from what I've read, one of the highly valued gkrellm or conky -displayed details seems to be the session network ul/dl traffic tally -- welcomed by people using dialup or metered connections.