I have the Viking 875Q...I have been in love with a Viking D1 for years but wanted a larger throat so I got the 875. I also have a Janome 8200..I will say the machines are really different. The auto pressure foot on the Vikings is great for piecing and especially for appliqué. The Janome sews much faster but I'm having trouble having to raise and lower the pressure foot because I'm spoiled. The Janome does have a knee lift but because the machine is so long the lift is too far to the left for me.
I have always had Vikings and never had a problem (just got the 875Q so don't know if it will be trouble free)
I think you should take a long test drive on both machines. Take you own fabric and thread you usually use. Thread the machine, wind bobbins, sew and spend at least 30 minutes on each machine. Then you MUST consider the dealer and how you feel about them. Don't make you decision until you decide which one you like. You will be happy with either, but you don't need both machines like I have. Good Luck