I've built with block and poured. As long as the block is covered by membrane waterproofing and all other water resisting measures are taken it is just as satisfactory a material. Some engineers I've spoken to prefer it to poured for its consistency and bearing strength.

Block used to be considerably cheaper than poured in my neck of the woods. But now it's very hard to find blocklayers, so I don't even bother trying.

I think many people would say poured walls are superior because they are monolithic and thus stronger and less prone to cracking if properly installed.

Since you're building new, check out the new foundation systems that use styrofoam forms that remain a part of the foundation walls providing interior and exterior insulation. They have reached the point of being cost competitive and provide many benefits. One builder I've known for at least 40 years says he will no longer use any other system.

If the builder makes a mistake with blocks, it's much easier to repair because of the ease with which they can be removed by lateral force during construction. Poured concrete at 30 mpa even three days after the pour is very difficult to work with. Lots of effort is required even to widen a beam pocket.

And unlike blocks, poured walls are subject to extreme variations in strength depending on on-site conditions and pouring skill. Many foundation guys still haven't got the message about vibration, for instance. If you're not looking, others might add water to the mix to make it "easier" to work with. OTOH, if the blocklayers can't mix mortar properly and don't reinforce with mesh and rebar you've got the same strength problems.

ICF forms have been around for more than 30 years. Unless you're in the South, where Codes restrict their use, they're an excellent choice. Super tight with great insulation value and ideal climate for curing concrete.

The dozens of tie holes in concrete forms and settling footings mean poured walls are no less subject to water leakage than blocks. They key to either type of wall is installing the membrane waterproofing, plus of course proper weeping tile installation, free-flowing backfill, grading and downspouts directing roof water away from the perimeter of the home.