I had some problems initially with my Furia and the contacts. Cleaned them a dozen times and it has been working now for a couple of weeks - but I'm struggling with the old tech (getting my head round it and remembering stuff I used to know - just been very much WinUAE over the past 15 years for a couple of games).
My furia likes to boot but, without holding the right button, boots with 4 meg missing. I can get this booted with all the memory if I disable cpu cache. I also cannot get furiatune installed as the gui tells me I have no furia card installed despite the OS in Shell showing the cpu and memory being a furia 020/04 and fpu with 9.5meg of ram. I'm still working on it and know this issue is solvable, so I'm okay with it as it's a hobby and expected.
I'm using a CF sandisk 8gb with adapter from amigastore.eu, which seems to work fine (although they are a difficult store to deal with if it doesn't go smoothly - which is a real shame).
It is quick though and I have mine with an active fan. This fan is fairly quite, but not silent, but that doesn't bother me. I also upgraded the ROM to 314 and the OS too, and am still in the process of getting that looking lovely, just not there yet. I think for the price they are amazing. The 600 certainly is a good retro-buy as the machines are better value than the a1200 (just no AGA - which is a whole debate on these forums) and the accelerators and additional RAM is a decent price. I've even put a nice Indivision ECS scan doubler in mine and that was only about 130 quid with delivery. I remember back in the day these were fortunes to get your hands on.
I think Storm may be right about the Red Devils, but they look really nicely made and do work.