Thanks very much for your response - I thought for a while you were managing to keep your 400Mhz miners under 60°C in a warm ambient environment! 
Running @ 350Mhz in a warm environment I'm getting temperatures of about 68/72°C. HW errors = 0.0012% which I think is pretty acceptable judging from your response. I would like to overclock to 380/390 however my only concern is whether or not running the miner at these temperatures, and higher, will affect the miner's lifetime..
Keeping HW errors low is a good sign that it's running well, but surely 70+°C couldn't be too good for it...I'm not sure..
Edit - I will send you a small tip when I get home, really appreciate the models!
Running @ 350Mhz in a warm environment I'm getting temperatures of about 68/72°C. HW errors = 0.0012% which I think is pretty acceptable judging from your response. I would like to overclock to 380/390 however my only concern is whether or not running the miner at these temperatures, and higher, will affect the miner's lifetime..
Keeping HW errors low is a good sign that it's running well, but surely 70+°C couldn't be too good for it...I'm not sure..
Edit - I will send you a small tip when I get home, really appreciate the models!