For money Quality which is better arcam or NAD?

In terms of reliability both brands have a good reputation so I think you are free to choose between them based on other criteria that are important to you like sound, features, looks, etc. I have owned both brands and never had any problems.

I'd pick the NAD. Personally I find the Arcam to be flat sounding.

Reliability-wise, I have owned an Arcam amp for about 2+ years before selling it to another user. After about a week the new owner called me to inform the transformer blew up.

Bizango...Rawr is NOT free to choose between them...he's bound by principle to be guided by our opinions and, unfortunately, I don't have one.

What do you have in your system?

I have owned the NAD C340 and C350 and also the Arcam Delta 290 and preferred the Arcam. Contrary to Ryder's experience I found the Arcam to have more depth as well as a smoother, sweeter sound. The NADs were enjoyable as well (the C350 more so) but different. More punchy but somewhat grainy. Not as refined as the Arcam but more rockin'.

Hope this helps, unlike some of the other answers in this thread.