Cement board is a good durable siding but there are cheaper options that are better looking and less durable.

Looks like the house has the 'designer' vinyl, which is the cheapest, and cheapest looking of the bunch. I would price out cement board and a vinyl in a traditional 6" to see the price difference, but given that you don't have a large area to cover I would imagine that the cement board isn't that big of an upgrade.

As far as bang for the buck, I think you would want to upgrade the kitchen and bathroom builder grade cabinets and countertops, do something with that awkward attempt at creating a foyer, and put in more neutral paint colors without the contrasting colors between the walls and the sides of the tray ceilings which the previous owners seemed fond of.

We are eliminating the wall between FR and kitchen, pulling all the overhead horizontal furred down boxes in kitchen and foyer, relocating upper cabs in removed wall to a bar construct in the eat in by kitchen, tiling kitchen to garage hall, bath and utility room ...

Sorry ...didn't complete ...absolutely going neutral on colors. Have appliances in order. Only concern about taking wall out is noise, but the way it is now, the wall tends to cause echo and magnifies noise in the kitchen that escapes over the top of the wall into the vaulted family room.

The front facade looks so dull compared to the houses around us ...

When spending a couple of hundred grand, expert advice from a designer so that it doesn't go pear shaped is a pretty good investment.

Sophie - I can't tell what you mean with your comment ... this isn't rocket science ...i just want to freshen up the front facade of a house that costs the same amount as what you believe someone would spend on changing the facade ... not sure how pears get involved?

She gets fruity sometimes

Get something fire rated, concrete board or steel. Future roof could use fire rating as well instead of asphalt. They have steel that looks like shingles now.