I echo Silver Fox. Go with SS pins. Not trying to troll your question and downplay the two vibratory tumblers you've chosen. I've used the Hornady one blissfully until I realized that there are better methods out there. I don't think I could go back to walnut media again.
I recently used a Thumler Model B high speed until I bought a Rebel 17. I didn't know that they use the exact same tumbling barrel only the Rebel is powder coated and has better securing nuts. The Rebel 17 base and motor on the other hand is far superior. There really is no comparison. The Thumler has plastic bushings whereas the Rebel has enclosed bearings and a better motor. Whats the different for cleaning you ask if both have the same barrels? The Thumler can hold 15lbs and the Rebel can hold 17lbs due to better motor and bearings. The weight limits are very misleading as the Thumler model B can only clean about 2 lbs of brass but the Rebel can clean 4 lbs. This is because you use almost gallon of water (about 8 lbs) and 5 lbs of stainless steel pins.
I bought my Tumbler from treasure seeker initially then bought my Rebel 17 from h ttp://www.stainlesstumblingmedia.com/ The shipping cost was high but if you buy the Rebel and ss media combo it will help offset the awful shipping costs. I was the first Canadian customer they had and asked for feedback on the entire shipping experience. I told them although it only took 3 days to get to me in Canada the taxes, DHL shipping rates and custom fees were incredibly expensive. Not sure if they've changed their shipping to USPS (not UPS) yet, but buying a Thumler and media in Canada is about $10-20 bucks cheaper. For me, having twice the capacity was worth the difference since I had about 7-8k of various brass casings to clean with my friends.
For reference, in the past I've used a vibratory tumbler and walnut media, sonic bath and rotary tumbler with SS pins. My best results are using the rotary tumbler with 5lbs of pins, tbsp of Dawn, half teaspoon of lemishine (from Cdn Tire) for 2.5 to 3 hours then dumping my 4 lbs of brass into my sonic bath with a squirt of dawn and 2 teaspoons of lemishine for 30 minutes to finish any remaining residue in the primer pockets and the bottom of my 308s (didn't find the sonic brass cleaning solutions any better for the money). Arguably for my 9mm to 45 ACP, I could just let my rotary tumbler go for 3-4 hours and be done. The sonic bath produced very good results on it own except mine only has a timer for 30 minutes and didn't do as well as the pins for the stuck on residue.
BTW, the website above has recommendations for cleaning and equivalent brass quantities. Very helpful if your starting out. Silver fox and the others helped me get going on SS media and I've never looked back.
