Yes, i guess! I've such Sylvanias too. They are pretty good for voices or strings but the Telefunken do this job too and they sound stronger, bigger and more powerful. As I wrote, 10 from 10 points. The Sylvania are nearby, I give them 9 from 10 points.
I used to run on those Sylvanias, but recently I switched to my gold and platinum plated Voskhods. I sort of like them, so I didn't switch back for more than month now. I did some comparison with Mullards and Telefunkens, and even my girlfriend (who normally doesn't seem to hear difference) thinks Sylvanias and Voskhods are best (she actually pointed to Voskhods as her favourite, but she said it's about their looks - ya know gold/platinum looks great ). So I decided to give another chance to Voskhods (which I previously considered not that detailed). I dunno, Sylvanias were very good, maybe too good, maybe too clinical. I got a bit bored maybe. Voskhods make me actually want to listen to the music. I tried Telefunken several times, but I got bored just after 1 minute of listening to them, so it's no go for me