I've fished with a double handed rod since the mid-70's. I own a closet-full of rods between 12 and 16 feet long. I am an avid steelhead and salmon fishermen and to this day, with all those years of fishing with a double handed rod, have never made a Spey cast and don't intend to ever make a Spey cast.
I think it's a completely over-rated goofy approach to fly casting and is driven by marketing more then anything else. The decibels of the Marketeers like Rio have pushed the word so hard that somehow, it has taken over the term "fly casting". When I hear people say..."I got one on the Spey" it's like fingernails on a blackboard. You mean you caught a steelhead on a fly? No, I got one on the Spey, they say, not aware of how silly they sound.
You sound quite pleased with your purchase and I'm not trying to poison your water. I'm simply alerting you to the fact that the entire concept of "Spey" is hugely over-blown for one reason and one reason only---to sell more rods and lines.
First, it's an incredibly disruptive way to cover water. Planting that "D" then ripping the line off the water is a perfect way to scatter all the fish at your feet and send them to the farthest reaches of the opposite bank. So when a "Spey" guy plants his numerous "D's" as he makes his way through a hole and finally gets one on a 30 meter cast, he pats himself on the back for his stunningly profound distance cast, completely oblivious to the fact that the same fish he hooked could have been caught with a 10 meter cast if he had been more stealthy with his casting abilities to begin with.
I once posted similar comments about how disruptive "Spey" fishermen are on Speypages and a British guy immediately chimed in, almost hyperventilating he was so happy to see he was not alone in his suspicions that "Spey" casting was hugely over-rated and completely disruptive to the river and disruptive to anybody else fishing around the Spey caster.
You say you want to fish "small rivers" . Why on earth would you want to use this casting technique on a small river????? A simple overhead cast will cast the large weighted flies you said you want to use with pin-point precision (if your leader is properly balanced against the rod and line you're using). If you're in a tight spot, roll cast. Planting that "D" is just a glorified roll cast with the regrettable collateral damage of lots of exploding water.
My family lived in London in the 70's and 80's. I fished the Tweed and the Spey several times when visiting them. Not once did I see any of the fly casters on either of those river "Spey" casting. They all used overhead casting techniques and covered the water just fine with the brass tube flies they were using. Seeing that, I purchased a 14 foot cane rod Sharpes rod and used the same technique I saw them use and never looked back.
Later in my fly casting career, I met Jim Green who was probably the first guy in North America to start making double handed rods at the Fenwick facility on Bainbridge Island (now the Sage facility) Both Jim Green and his wife were reknowned as long-distance fly casters and won many international awards. Their preferred cast? An overhead cast. It was so elegant and so effortless that I took it upon myself to learn it and have fished that way for many years.
Take a look at this video. Read the comments of people who watched it. I guarantee you that if you take to heart the technique that Jim Green is promoting, you will never mention the word "Spey" again, nor will you have to:
When I see "Spey casters" on the river I generally leave the hole and find other water, especially if they're below me. They leave the water so beat up and the fish so spooked I'm better off leaving.
A good friend of mine guides on the Skeena. He's seen his share of fishermen. After a few drinks he started complaining about some of his American clients who insist on "Spey" casting, planting their "D's", detonating the water, then insisting on casting farther and farther, completely over-casting the fish (Skeena fish lie close to the bank)
Why do you think they do that I asked rhetorically.
I have absolutely no idea, was his response. Perhaps they want to show how far they can cast. They just don't know any better.