If you're looking for a cruiser I don't think you can go wrong with either.
My personal preference: The Yamaha.
The 109 has more power and I dig the look but they just sound terrible.
I'm a big fan of Yamaha's air cooled twins:
1) because I like the simplicity and clean look of an air cooled engine on a cruiser
2) they are TORQUE MONSTERS.
3) they sound FANTASTIC with a set of pipes.
4) they have the perfect amount of 'character'
For me, the feel and sound of a bike is a BIG part of the experience. If I don't feel like a bike sounds good it just takes something away from my riding experience.
I was at a charity run last month, an older gentlemen had a raider 1800(I'm pretty sure that's what it was). After BS'ing with him for a few minutes, he insisted I sit on the bike. He was a small guy, and I'm also far from a big guy, but what the hell. I hop on and that bike was So friggin easy to maneuver, it almost felt like a 650 metric cruiser....compared to the Boulevard, VTX 1800, etc. The only problems "he" had with the bike, were the exhaust burning his right leg, I believe he had Aftermarket pipes and they stuck out farther.
It was a sweet bike, I don't think it's meant to be a long distance cruiser, lack of storage room and passenger comfort etc, but it's got the big V-twin thump, with the hotrod looks.
I've ridden both of them a friend R and the Raider at a Yami demo. The Yami was confortable while riding but seemed to run out of breathe really short. For the size of the bike it handled really well like mentioned before almost like a much smaller bike. I think the R is a bit more sport minded ride with in my opinion better performance overall. The off the line scoot from the big V twin was pretty good but seemed as though you had to peg it to get going at a good pace and seemed as thought the smaller Stryker had a bit more pep. Thats just my 2 cents.
Love my M109R LE. Just bolt ons and 110/108 at the wheel. Very torquey. Very big. Very loud...with Hard Krome drags.
I know nothing about the raiders, but ride with a Stryker. Like it, but not even close to the same league as the 9.