The Vanguard Sporter has a walnut stock. I don't believe a Howa 1500 is currently available in walnut, but last I saw it wasn't
nearly as nice. Also, Howa standard calibers have 22" barrels vs. a 24" on the Weatherby; you pick which one you prefer. While they share the same action, the 1500 and the Vanguard Sporter are significantly different packages.
I have a Vanguard Sporter in .30-06 and it shoots like a dream. Wonderful balance, helped me win a multi-gun club match; I used it for the offhand rifle portion. It really shoots offhand exceptionally well, just sits there in my hands. Accurate, solid, and the stock design and fit are perfect for me. The Weatherby comb works very well in providing a solid cheek weld, but recoiling away from your face.
It is not a light gun. It's not overweight, but it's definitely full-size. That's the one caveat. If you want a light carbine, this ain't it.

I use it for deer hunting in the mountains and high desert; it's not too heavy to carry. But it's no featherweight, either.
As far as a full-size rifle goes, I love my Weatherby Vanguard Sporter. No plastic, either.