Best Corded or Cordless hammer drill for concrete?

[UNG]

The problem of choice really starts with the OP's question as the best machine is the one that is best suited to the particular task in hand, a machine for drilling a 6mm hole will be different to one for drilling a 100mm+ hole and if you want to break up concrete then there will be a different one again
A mate of mine was a manager in a hire shop before he retired and if I called in for a brew it was amazing how many customers didn't have a clue what machine they needed and generally were after hiring a lighter weight machine than they really needed and they were surprised when they were told the limitations of each machine
The favourite one was generators you know the ones that provide limitless Kw of electricity, one guy was expecting to run an event with a load of 30 - 40Kw off a 5 KVA generator and was really miffed that they wouldn't hire a generator to him and gave him a couple of phone numbers of a few companies that could supply generators of a capacity he needed

The user abuse factor always makes it difficult to recommend any equipment, some people with a bit of care can quite often get away with using a lesser capable machine to complete a task, then again about 5 years ago a site I was on the builder managed to burn out a brand new Makita core drilling machine while using a 110mm core bit without getting through an 11" wall, I have the same machine lost count of how many large holes it has cored in the last 25 years and it has only had the clutch tweeked once in all that time

 

[Carolina]

Masonry bits are rotating chisels, they don't 'cut' as such. Therefore the progress in masonry is made using a hammer action.
In drills with 3 jaw (keyless) chucks the hammer function is actually called 'percussion' and is not heavy enough to drill holes in the denser masonry materials such as concrete, engineering brick, 1930's houses etc.
For those materials you need a power tool with a 'rotary hammer' function which is mainly found these days in SDS (plus or Max) tools. These tools have a pneumatic hammer inside the chuck which hits onto the end of the drill bit or chisel. In a percussion drill, the 'hammer' is produced by the mechanical backwards and forwards movement of the chuck. In a nutshell, they don't whack it as hard

So that's why my drill gives up on making holes after the first 3cm, I tried pushing it a bit and the bit got stuck inside the wall, luckily the motor survived that.
I was looking to install some surface-mounted boxes for sockets as well as some fluorescent fittings on my basement but the walls said no, there's only one lamp holder that's basically hanging from a beam with a tiny 25W light bulb for the entire place, sort of creepy down there.