and pretty much discontinued renderers.
Naah still alive and breathing.
Arion and Indigo are specialised in what they are trying to achive.
Indigo pushed for a novel light transport method, but quickly found itself in the shadow if Maxwell render, which did that even more specialized than indigo two years prior, which is why all the Rolex and diamond shots ended up there instead of with indigo.
Random control's arion basicly played Pixar in their need for an in house renderer, that they molded to their needs. One of those was a strong Framebuffer with a ton of smart HDR functions, which became so popular, that they sold it seperatly and more focus on artsy control. (Best render elements handling of any renderer to date, their pretty dope atmosphere simulator, hair and fur)
Both specialisations don't hinder someone doing archviz, but don't exactly help you out either.
Also both were build as a primarily GPU accelerated renderer. If you used Corona, you probably have a kickass CPU, which these two didn't have their main focus on being the fastest with.
Honestly, if you have a bad relationship with Corona, your best bet is Vray, since they are not too far away in style.
Lastly, there was a thread of people comparing render farm costs, but can't find it, since I didn't have any useful info to post and forum search doesn't turn it up for me. Maybe someone can link it.
Hope your licence stuff gets resolved and/or good luck finding a new way.