Hi and welcome to the site. I just got my hands on an Oscar a couple of days ago so only have limited experience.
I bought it for the office and use a Giotto at home. The obvious difference between the 2 is the package - lots of shiny stainless steel in the Giotto, while the Oscar is all plastic.
I have not done a side by side comparison but so far would say te Oscar is capable of producing an equally excellent shot. Steam power is huge, even more than the Giotto. That could be because the Oscar has a 4-hole steam tip.
The Oscar is the cheapest HX machine on the market. Others start at around $2K.
1. High quality non-HX machine such as the Vibiemme Domobar Junior or Diadema Perfetta. Perfect if you are only going to make 2 coffees at time. Not so good if you do a lot of entertaining.
2. Second hand well-cared-for HX machine.
3. Something a little different?
Also, do you have a grinder?