Pros
It's impressive to see a beating heart outside the body; the product gets attention from prospective employees and from the media because it could help patients. The founder/CEO has a big vision and has been very good at fund raising. Unfortunately he doesn't seem to have the skills to execute or to lead a functioning team.
Cons
Very difficult place to work due to the culture, with significant financial struggles and repeated layoffs. The founder is extremely controlling and has created a culture of blame and distrust. He consistently degrades his employees and seems to blame the company's failures on everyone around him, but seems unwilling to listen to experts and even actively discourages employees from communicating with each other. The company has had serious problems with the FDA and has failed to gain any commercial traction outside the US, where the heart and lung products have had regulatory approval for years. Economic practices border on irresponsible, with all expense paid meetings with customers at the Ritz in the Caribbean, first class travel for the CEO and executive team, yet many vendors complain about not getting paid on time and the majority of employees don't receive raises or bonuses. The founder seems to routinely lay off and then hire new teams all over again. He throws public tantrums and trashes the reputations of people that have worked for him and work for him now. He even expresses deep resentment and anger at many of the customers. Many of us stick around despite the toxic environment in hopes that he'll get replaced and we can IPO, but if that doesn't happen soon I don't see how he can possibly make any more promises to get another round of investors. Potential new employees should be very careful before accepting an offer form this company if the founder is still the CEO. Find and talk to former employees and research the financial history of the company before making a decision.