I find the Nokia 6500 Slide and....
WH-700 Stereo Headset combo to make for a very potent music phone.
I've used the SE W series music phones. And, while they're nice, SE tend to screw them up as good all-round multimedia phones by limiting the camera functionality.
When my beloved SE W810 got pinched I opted for the Nokia 6500 Slide and WH-700 Combo as a replacement.
The insurance company initially tried to offer me a SE W910 as a settlement. However, after feeling how flimsy the damned thing was I wouldn't accept it. Luckily, for me, the 6500S got discounted the next day, and I was able to get that instead. And, since I only had to pay a $150 (NZ) excess charge for the whole package, I was supremely happy with it.
I've read a lot of negative reports regarding the 6500S' buggy firmware. However, I immediately upgraded to the newest when I got mine and have had no problems with it.
The music player is quite good and takes a lot of it's functionality from the XpressMusic series player - not the "say and play" function though. It does all that I want it to: sorts and selects by album, artist, genre; allows for custom play-lists and custom eq settings; shuffle and repeat; displays the album art, etc..
The WH-700 Stereo Headset I can't praise highly enough. The sound quality is fantastic and competes well with anything SE would include in their packages. And, it definitely blows away that crap that comes with the iPhone. It has volume and player forwarding controls built into the mic dongle, a nice storage box with a somewhat odd cable management system, and is made of very stylish chrome and black material. Nokia was even thoughtful enough to include a 2.5 to 3.5 mm adaptor in the kit.
Another bonus for me was the appearance of the whole kit: A lot of music phones tend to be geared toward teenagers. So, they're brightly coloured and made of plastic. While I personally don't mind this, I'd look like a tool with such a phone, as I'm a 46 year old man who needs to project a certain image because of the industry I work in. However, I needn't concern myself with this when the 6500S is within the sight of others. The stainless steel casing, with high gloss black accents, looks very flash without being over the top and outlandish.
Anyway, enough of my praise-singing. ;)