Those small hand moved/operated rental units will beat you to death. I did that for two 3' across stumps and "never again!" If you are renting something get one the 4 wheelers that are hydraulically operated. Expensive but worth it for a big job.
Ron
I tried to rent the Vermeer but it was not available. So, I ended up with the Rayco which was a good machine. I put 6.7 of the allowable 8 hours on the meter in the 24 hour period I had rented it. I also had to allow for one hour transport each way, cleaning, loading. and darkness, I rented it overnight so I could rest overnight between grinding periods. It's not particularly hard work, but you do need to pay attention. I have a chainsaw logger's helmet with ear muffs and face screen which is good, because it does throw some chips your way on occasion. The work station is to the side so you can see what you are doing, which is good, but you have to keep your head turned to the side which gets old after a while.
This is a four wheel machine with hydraulic motion, steering, and cutter left, right, up, and down. It worked well, but it still took some time to do a large stump. I managed to do ten stumps which were the ones closest to the house and the largest. So, I got the most important ones. The local "for hires" here would just charge for the machine rental and add an hourly fee so I didn't go that route.
Depending on my motivation, I might rent one again (maybe Vermeer this time) and do the remaining less important stumps.
Just FYI, the machines were available from two different rental companies. The Jayco was $250 per day and the Vermeer is $265.
