No assembly required, there is a lever to raise and lower the top part over the bowl. The bowl is a pretty good size but feels a bit flimsy - definitely on the cheap side. It has handles which is a nice touch, BUT they have been attached to the bowl and are not part of the actual bowl.
There is space inside the mixer at the back to feed the power cord into - though it's not retractable and it seems to be a case of feed it in and hope for the best.
In terms of size, I have found a home for it behind the kitchen TV - it's not too wide BUT I had to remove the bowl as that does add to the size quite a bit. It is a lot longer than (eg) a Kenwood as the blender gets mounted at the rear.
The lower settings felt quite powerful and blended butter and sugar well - I only needed to scrape small quantities from the side of the bowl where they had splattered during mixing. However it was making so much noise and creeping slightly across the worktop when I turned it higher so I definitely wouldn't feel comfortable leaving it unattended!
The blender does not have huge capacity so I will not be getting rid of my stand alone blender.
Having eaten the cupcakes I made with the mixer I think either I didn't leave it running long enough, or it's just not that efficient as I did have lumps of sugar in my cakes - which definitely weren't there when the sugar went in.
My Mum has a Kenwood K-Mix and I think for the extra cost (£70 at the time of writing this), if you're going to fork out for a mixer I'd go for that. Kenwood kMix KMX54 Stand Mixer, Peppercorn Black