I would say that RoseHosting has provided a quality and reliable service at a reasonable price. My experience is that of a small business (brittfranken.com: photography). I have not tested RoseHosting VPS with regards to scalability (yet). With that said, for small businesses, requiring a certain technology freedom, RoseHosting VPS is a great solution.
I have tested more than 20 hosting services in the past at WHSR - RoseHosting is easily one of the top 3 in term of server quality by far.