I painted a lot of those on commission a few years ago, absolutely stunning miniatures, some of the best sculpting and detail I have ever seen on such small figures.
They are "true 30mm" elves, so very slight and slender looking, their proportions are only fractionally larger than you will find in Esci/Revell 1/72 plastic figure ranges.
They will make your GB figures look bulky and out of proportion (which they are). If you have to mix them with other ranges then look at the older GW plastic LotR figures (not the bulkier metals) or the Mantic KoW elves and humans.