No offense taken at all Andrey. I'm such a "list" person and read much better that way, so I laid it out better for me, hoping it might help you as well.
Andrey any camera will fail to deliver if the photographer fails to plan.
The type of camera and is really not that important. i.e. My best photograph to date (IMO) was taken with a 35mm Pentax MZ50 with a bad,
really bad zoom kit lens. I still have that camera and love shooting with it although would love to find a good prime lens for it instead. Commercially I currently use a Hasselblad and a Pentax 645NII. That's because I love how they look and work mechanically. They're great tools to work with and they help me take different types photographs. Both work well in low light - but that's up to me to make it work. I can't blame Pentax or Hasselblad if it takes a bad picture. I also have a Mamiya C33 which I affectionately call my "brick" and absolutely love photographing with it.
APUG is a great resource for information, help is always a few clicks away, full of wonderful people, interesting and entertaining debates which anyone can choose to ignore or roll around in - and totally addictive and expensive - especially if you get sucked into the gear-head groupies.
Therefore, I highly recommend you try out (borrow/rent/hire) different tools recommended to you, to see which fits your needs and style of work best.
I really wanted to buy an old red Porsche 911 because they are sooo cool!! So I took it for a
fantastic test drive, totally loved it!!! but so not practical for my family. But then again.... they can pull a trailer, right?
I'd also be happy with an old Holden EK or whatever they are called. Hmm but then again, I'm female and reserve my right to change my mind at any given time.
Hope to see you at the Colorado Foto3 Conference this year.