your opinion on buying an older Simaudio i-5 integrated

I’m a young audiophile and I have the opportunity to purchase an older Simaudio i-5 integrated amplifier from the early 2000’s from a friend. I’m curious what folks experiences are with an older integrated solid state amplifier from that era. Obviously I’m concerned about value and the longevity of the product. I know Simaudio is a respectable brand which makes me feel more comfortable. He’s the original owner and I believe he would have treated the amplifier well. 
I currently have a class D amplifier from red dragon audio that I’m happy with but I’m open to trying something new that perhaps gives me an opportunity to own a fine product at a very reasonable price. I’ve even heard of the i-5 being used as a preamp, I believe it is dual mono. It would be driving a pair of kef LS-50s. 
Appreciate any input or personal experience!