The second controller arrived today so I was able to play with it to verify it works. For most part they are similar but they do have slight differences.
To show the size of my hand with the Avenue pad. The pad has the same thickness and depth but is oh about 1/4" (1cm) wider than standard PCE/TG-16 pad.
First the obvious: Blaster is a tad smaller and it seems a bit more comfortable to hold it because of the curved design.
However I felt I prefer the larger Avenue pad instead. I guess Blaster would be fine for those with smaller hands than mine but each to your own opinions.
Second: the switch on Blaster isn't marked, I had to figure it out. With the switch (on the bottom, near my right pinky in the picture) positioned to the left, it sets button 3 to Run. With the switch in the middle, it maps to Select button. The switch in the right side seems to disable it as I don't have a 3 button specific game to test with.
Another difference: the rapid fire. On Avenue pad, the setting are: single fire, auto fire, and hold. Hold as it implies, "holds" the button 3 down. It is great for certain games like Gradius to map that button to pause and use the hold feature as gehtto slo mo function. On Blaster, it has single, slow hold and fast hold. There is no "press to rapid fire" mode like the second switch on Avenue. I found the slow-hold to be slow and choppy for slo-mo and I have not found any use for it yet. Fast-hold is about the same speed as Avenue hold (since both runs the same timing from host console) and can also be used for slow motion in games.