I’d go with the Clarisonic Mia. I own the more expensive Clarisonic brush that features 3 speeds, but I really don’t find myself using more than one. The Mia is great for packing when traveling it’s definitely more affordable.
I tried the Olay Pro brush — HUGE disappointment. After using the Clarisonic, the Olay Pro felt like it did nothing at all.
If you want a good investment that doesn’t break the bank, go with Clarisonic Mia.