I use a handheld meter, always have. Not smart enough to do ratios with the fill flash, so I just meter for the main and adjust fill light or bounce flat as needed.
it saves time when used right even in age of digital photography.
when using mixed permanent light sources with flash it is almost necessary if you don't want to spend time try-erroring the desired output.
On other side, grown up to predict exposition already so good that if my hensel remote would have 5 channels i could live without any even in studio.
