I use Bricscad pretty much every day. (v7 & v9 Pro) The v7 is needed to support a third party app yet to update. I can provide a bit of info for the interested.
Some details about our usage: Drawings are cadastral surveying, site plans and residential development, typically local roads and generally < 20 lots with occasional larger multi-phase longer running projects. We generate 2D drawings with most jobs on a single sheet. The engineering drawing sets are generally max 5 sheets with the infrequent 20+ sheet project. I use a digitizing table sometimes and some raster backgrounds. My drawing files are typically in the 5MB range. My customization is primarily Lisp, scripts and button macros. (I hope to fall into the deep abyss of ARX soon).
My user experience is generally good. My Lisp code runs great and supported VLisp is pretty extensive and still improving. There are some functions I wish were there but I think most of what I have bumped into will be addressed once a release with the new geometry library comes.
I was around Autocad quite a bit up to 2000i but not much since then so I cannot provide a feature comparison (and likely do not know what I may be missing). I find Bricscad generally stable. There was steady improvement done during through the v8 cycle as the re-write progressed. The transition to v9 was a little bumpy initially but stabilized fairly quickly.
I find the support quite remarkable. My user related problems (I am not an expert CAD user) yield useful advice and recommendations. Bug reports are generally acknowledged within days and the reply often includes a time estimate for a fix. A release to fix reported bugs has been made within a week or less on more than one occasion. The user forums and support request system give me a positive feeling Bricsys place a lot of importance on user input. There have been issues and I have cursed while using the software but when it has happened I was listened to and someone was focussed on my problem. Generally I am not a fan of the web-based-support-ticket style support but it has been working well and has won me over.
My knowledge of the Linux version is limited. The current Linux version is based on Wine and I believe it to be problematic for recent distros. Bricsys has utilized wxWidgets in Bricscad (starting with v8) and are now nearly MFC free. The next Linux release will be native (not Wine based). You are all likely aware of all this anyway.
Time estimates are by no means firm but they have stated their current planning is for a beta of the native Linux version by the fourth quarter.
Everyone should try things for themselves in their work scenario. I and not trying to "convert" anyone, I only sell survey services but I can say I am happy with the choice to purchase Bricscad and have felt no regret.
Greg