An IG window unit includes a coating supported by a glass substrate. The coating includes at least the following: a dielectric layer comprising silicon nitride; a dielectric layer comprising an oxide of titanium; another dielectric layer; a layer comprising zinc oxide; an infrared (IR) reflecting layer comprising silver on the glass substrate, located over and directly contacting the layer comprising zinc oxide, wherein the coating includes only one IR reflecting layer; and an overcoat comprising (i) a layer comprising tin oxide and (ii) a layer comprising silicon nitride located over and contacting the layer comprising tin oxide. The IG unit may have an SHGC value of at least 0.65, a visible transmission of at least 70%, and/or an Energy Rating of at least 25.