I've been looking for a 30-40w practice amp with built-in modeling and I got the chance to test the Cube 40GX and Mustang II side-by-side with my own guitar at mid-level volumes in one of the local guitar stores. For me, the Cube won hands down. Here's my opinion of why that is: 1. The Cube's 10" speaker projected really well and had none of the muddiness that I heard in the Mustang 2. Even though the Mustang has a 12" speaker, it didn't sound any louder than the Cube. 3. The Cube's effects were better - duh, they're the classic Boss effects 4. The effects switching was faster and quieter on the Cube 5. The controls on the Cube were SO much easier - setting up anything except amp models was hard on the Mustang 6. The Cube has 3-band vs. the 2-band EQ on the Mustang and the controls (especially the mids) make a big difference 7. With the added FS-6 footswitch you effectively have a 3 channel amp (JC for clean + 2 other tones/levels) 8. Finally, the JC clean is just the best - full bass, lush mids, and high-end sparkle and just the right of dwell on the reverb and chorus Price-wise, the local store price matched online prices without me even having to ask. Even though the Cube was $50 more ($249 vs $199) it's still a screaming deal for a 40W amp of this quality.