I fish both ways (fly and gear), and often use a Spey rod. While they're nice, they're not necessary. Even a relatively cheap one is going to set you back at least a couple hundred dollars, not counting reel and line. Unless you're a nut for it, like me and some others I know, I'd stick with what you have.

But if you do go for it, they're a lot of fun, and once you've done it, you'll never go back.

What they are best for is the long runs where you are covering a lot of water with the cast, swing, step routine. It's a good bit easier to quickly get a long sinking line out with mr Spey than a traditional fly rod. They will cast a long way, though a competent hand with a normal fly rod can usually get as far.

I use a Sage 13 1/2 foot 7 weight, throwing a 7/8/9 line.