Be careful how you understand the warranty. All new sewing machines come with this kind of warranty. It does not mean that all of the parts are covered for 25 years; I think it simply warranties that long against defective parts. Service on parts replacement would not be covered for 25 years, and parts that wear out due to use are probably not covered either. Since virtually all sewing machines come with this type of warranty, it's really not a consideration in terms of making a decision about buying a machine. The servicing is actually a more valuable deal, IMO, although the modern machines seldom need more than normal home maintenance to keep running fine.
I don't think the Elna brand is considered particularly good anymore. In that price category, most people would be looking at Janome or Sears Kenmore machines, or maybe Babylock machines.
There are user reviews of machines at
http://www.patternreview.com . Also Google elna 3210 reviews to see what you can turn up that way.