I go to the coast and Brookings often from Reno and personally I detest towing on 299. I think of it as a 120 mile corner with some steep grades, a couple of which are 8%. From Brookings I always take 199 up to I-5 at Grants Pass and south on I-5 to Shasta City. You can then get on the combination of Highways 89/44/36/395 into Reno.
On 199 in California there are a few narrow winding sections, but you can usually move along fairly quickly. Once in Oregon it moves fast all the way to I-5. On I-5 there are a couple of fairly steep(6%) grades near the border going back into California, but they aren't bad. When you turn off onto Hwy 89 South it is the most direct route to the Reno area and is a pretty good road, mostly 2 lane with passing lanes, and it moves fast. Once you get on US 395 just south of Susanville the traffic gets heavier, but you can stay on 395 all the way south until the turnoff into Death Valley. The only real headache along that route is the possibility of a late season snow storm. The last two trips from Brookings to Reno when towing took me 8.5 hours with some breaks along the way.