I think you'll do fine going with either. I almost went with varhosting but needed a clientexec panel. It was an a la carte feature with varhosting but included with the Site5 and Site5 was just a bit cheaper.
I've heard great things about both. Figure out what you need and see which one prices a bit better for the features you need. If you don't need clientexec then I would go with varhosting.
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