I haven't noticed any more issues with my Siamese then with any of my others. Mine tend to be good moms and usually not super aggressive. I had 1 that took a chunk out if me once and it was a Siamese Rex but then I have had others try as well. I do currently have 1 with a head tilt but again I had a black hooded with the same thing before her.
As for blues, I know someone who does great with them and I even have some of his stock. Blue females don't like me.. They tend to die while having or just after their first litter, but are fine up till then. I currently have 2, one is on her second or third litter and is looking awful, if she survives this batch I need to pull her for a bit, which I rarely have to do. The other one looks great but I don't think I have had a litter from her yet. But again, I know other breeders that do great with them!