Replacing Lath & Plaster?

[Manzell Blakeley]

Hello - I just got under contract with my first property! It's a large (4000 sqft) multifamily brick home in St. Louis. It's a "fixer upper" and not in rentable shape currently, and the kitchen and bathroom are both full-guts. Additionally, there is a lot of floor to replace. Lastly, the walls are lath and plaster, although generally speaking, they seem to be in good shape. 

Since we're nearing "Full Gut" territory anyhow, I'm wondering if it's advisable to remove and replace the lath and plaster and replace with drywall. I'm also under the impression that lath and plaster does not typically have insulation and I'm very desirous of keeping energy usage down. I'd prefer to replace with drywall, but I'm just concerned it won't be worth the budget (and FWIW, the unit has very high 9'+ ceilings).

What have you guys done on your properties?