They seem legit, though I've never ordered from them.
My go to sites are (in order of preference)
1) Here (PCF) - including the vendors
2) Apache Poker Chips (also a vendor here) - good site for China Clays,
MSK Plaques, Sample sets, some casino paulsons, (the metal slugged Casino Royale chips
are really nice chips for the money if you are looking at the claysmith price level)
3) brpropoker (also a vendor here) - ceramics with the some of the nicest artwork in the business on them (tiki kings, dia de los muertos, etc)
4) discountpokershop - they carry nice entry level slugged chips with good QC to them... Outlaws, Spartans, Lucky Horseshoes, Monaco Casino, Crown Casino...
these all have much nicer quality and feel to them than the chips that pokerchipmania carries for the same price... only downside is they don't sell samples -
but you can find samples of them cheap on
eBay
5) pokerchiplounge - another good site you can get samples from including most of the chips that pokerchipmania sells... they also make some nice ceramics
with nice color saturation to them
6) pokerstore.nl - good site for getting sunfly and other samples for reasonable shipping charges
7) pokerchipswholesale - they carry a lot of samples for cheap... their shipping however is not cheap... and they are constantly out of stock of like half their stuff
and of course there is always
eBay if none of the above work out.