Closer Examination
UE's design of the BOOM is iconic, and the BLAST's could very well do the same. It looks like a slightly more adult version where the BOOM is a tad more playful in its aesthetics. The BLAST has sharper corners and is a bit straighter when viewed from pretty much any angle.
UE's Power Up pad is an essential accessory if you plan on using the voice assistant a lot. It is well integrated into the design as you just unscrew the bottom screw and insert the one supplied with Power Up. The connector is basically a small cone with a small self-centering effect; there are no actual locks—there is gravity, so you can just grab the speaker when heading out.
Size-wise, the BLAST is very close to the BOOM, though still obviously dwarfed by the MEGABOOM. Diameter-wise, the difference is very small. The design of the bottom dust cap is much better on the BLAST, and UE's new Power Up add-on completely removes the need to unscrew the bottom screw. One feature that is gone is the mini-jack in. Its location was slightly awkward on the BOOM, so I for one am actually glad to see it gone.
Button design and layout is the same as with the BOOM. You get two huge +/- buttons for volume control and a large on/off switch at the top. By pressing and holding down the minus and power on, you disable the microphone array, which keeps Alexa from listening in on you.