I think the mustache and beard makes Sam look older. I liked him better before.
You're probably thinking of Sam's/David Ford's future look (in terms of these episodes) because Sam has consistently had a full beard ever since Ford took over the part in Ep #35.
Sam's full beard won't disappear until Ep #498 (which was featured in the slideshow just over a week ago) - though he will still have the mustache.
(Though, of course, during his brief stint as Andre, Ford doesn't have any sort of (real or fake) facial hair except for long sideburns - but that's still an upcoming storyline at this point, too.
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