Re: How Necessary is a Different Bowl
phunnel's were org designed for a brand of tobacco called Tangiers (Noir style), users quickly learned of the benfit of using them with dripper tobaccos so the juices stay in the bowl (where they help keep the flavor and session length longer) rather than draining down the stem (and causing a blinking mess).
MYA bowls are decent, I love the extra depth they have over say the Modern Clay bowl. Egyptian bowls are the org bowl for hookah, simple clay bowls, many of us love E bowls. There's even glass / pyrex bowls.
If your new to hookah, I say learn on the bowl that comes with your rig - once perfected you can branch out. It's not necessary to use/get other bowls, but you may want to keep a few lying around for accidents and such not.