Viking dealers are very good at giving 'owners' free classes to learn all the bell's & whistles- how to use their machines- they want happy customers- if you have not taken advantage of these you should call & set up a time to go with your machine- let them know what the problems are you are having and learn how to remedy them- Vikings have been around for a long, long time and they do have good customer service. if the problems are the machine and not (operator error) they will fix that too.
before deciding to just move on to something else I would try to figure out what is happening and fix that. I love my Viking- I did have to drive 160 miles round trip 4 times to take the offered classes and learn how to use my machine but I feel it was time and money very well spent. I have done a lot of sewing with that machine over the past 10 years.