I have been using Quicken 2003 under linux since cxoffice 1.3. In the pre-2.1 versions - my primary Quicken environment was still Windows (ugh!). However, with cxoffice 2.1 almost all the features work enough, such that I have eliminated my Windows Quicken environment.
Install is very clean and works fine. Online registration is still tricky and fails (I will put a workaround in Tips& Tricks).
All online features work - including online banking, register synchronization with brokerage companies (my Fidelity downloads work flawlessly!)
This is a workable environment - I am hoping that with the next release of cxoffice the remaining problems will be solved. I have posted several bugs with codeweavers that have been accepted and are being worked on (so I have been told 😊 )