i am really grateful for the benefits my company provides. i receive unlimited sick leave, seriously. only caveat is that if i am sick for a day longer than 6 months at a time (6 months stretch), then i am subject to a long-term disability leave, which means that insurance company pays for the salary pay, typically around 70 to 80 percent of normal pay. but up to 6 months, company pays the normal 100% salary and 100% of other benefits. i could theoretically be in at work one day every 6 months.
having said that, i have some of the best co-workers. hardly anyone calls in sick, since every position in my department is very vital (all of us are scientists). but when situations do come up, we all help out each other and i haven't heard anyone complain not even once. some people even put in 12 hour days without complaining to cover others' work. i have a co-worker who is battling cancer for the 3rd time in her life (and all 3 times while she's been employeed with the company). she has been away because of surgeries, chemotherapies, and radiation treatments. but the company is very supportive of her, and making her feel as comfortable as possible. she will have been out of office for at least 6 months, but she doesn't have to worry about her job security.
my company was named as one of the 100 best company to work for, by working mothers' magazine. i know a lady who is out for 4 months because she was giving birth. and my co-worker who is due in July, will be doing the same.