I'll be ordering a 150w SSS clone, and was hoping to get some tube recommendations. Many seem to think the GE 6550A is the best, but the fact that the mids are sometimes described as harsh, and mechanical, worries me a bit.....but I do like the idea of an open, clear, airy, top end. They're expensive as well. I would like to avoid tubes that will sound too Hi-Fi and have a hard feel. Definitely prefer a warmer tone with a softer feel, while still retaining articulation and clarity. Any recommendations would be much appreciated. Thanks in advance for your responses.