Is a burr grinder better than a blade grinder?

Yes for most brewing. Burrs crush beans to a more even size, while blades chop unevenly and leave fines that clog filters and taste bitter. Even extraction is the main reason to choose burr.

Will it grind fine enough for espresso?

That is uncertain. Espresso needs very fine, repeatable adjustment, and this grinder's burr type and setting range are not specified. It is a safer fit for drip, pour-over and French press.

How does it compare with a Baratza or Breville burr grinder?

Those brands publish burr type, step count and replacement parts, and offer more adjustment for espresso. The AROMASTER is a simpler stainless steel electric burr grinder with less documented tuning.

Does it have a hopper and a grounds bin?

The material does not list them. Check the product details for hopper capacity and whether grounds go into a removable bin or a portafilter holder.

Is the stainless steel body heavy?

Weight is not given. Stainless steel cases generally add heft and dampen vibration compared with plastic, which helps the grinder stay put while running.