Well my last three houses were all quite new and had all 3 systems basically and I wouldn't even consider combi unless my house was small.
Normal tank, bit meh, can see why people would go combi over it.
Combi, well ok, and despite being overspec and good water pressure you could still tell when you got more than one person using water
megaflow (ours is a rip off version basically), we have had 2 showers and someone running a bath more than once and its still got awesome pressure. This beats the other two hands down.
There is negligable heat in the hot water cupboard so its not losing heat of any significance, plus its a place where we dry out the odd thing like running shoes etc, plus its storage for spare towels etc, which would just need to go elsewhere.
Honestly if I moved to a house now that had had a tank replaced with a combi I would change the boiler back and get a megatank. It would be the first job I would pay for.
Last xmas the new gf of my other halfs son was with us for the first time and described the shower as the best she had ever had, my other halves daughter said yeah its epic because of the pressure, she looks forward to staying at ours as she has moved from rented to rented and most have old tanks or combis and they all suck.