The smell can be diluted if you use a spading fork to mix it in. The downside of weed seeds being in the manure is a tradeoff you'll have to make. I think a little extra weeding is a small price to pay for bulky, organic filler to fluff up heavy clay soils. Simply pile the stuff up on the ground, cover it with a large plastic tarp and let it sit for a few weeks. You can also compost the manure in a compost pile.
Fresh manure is a great addition to compost piles.
Even if you buy commercial manure in bags, it's still a great soil and inexpensive compared to most other fertilizers. A 4-inch layer spread over vegetable gardens, flower beds or established trees and shrubs, is a great way to improve soil conditions. Used under License.