I have tried Balkan before, but Kalpa not sure about their quality. The number 1 problem with Balkan is the bad PIP I experienced, but the gear delivered results.
These are okay... A lot of balkan is faked but if you get the right quality, its pretty good... I have not used Kalpa nor do I know many that have... Im a fan of Radjay and Bayer myself but once again, these are often faked so its hard to say but I have had good experiences with both...
I am working on bringing over some quality sources here that you can absolutely trust... I am working on A LOT of things for the forum and changes will be coming very soon... Just keep your eyes open in the coming weeks!