It's a great saw, offering an outstanding power to weight ratio with excellent reliability. Mine has cut an estimated 50 full cords of oak without any problems. Informal testing with my neighbors 394XP both running a 24" bar resulted in a 1-2 second difference in cutting time. So, it has nearly the performance of the larger Husky, without the extra weight. The Solo will also easily turn a 36" bar buried in red oak.
I also own a Makita DCS 6401 with Bailey's big bore kit. I prefer the balance of this saw over the Solo, it feels much lighter and nimbler. It also has stiffer anti-vibe springs and larger felling spikes.
The downside is the saw doesn't seem to be as well refined as the Solo. The gas and oil caps and the kill switch are not recessed and can get in the way when cutting. On numerous occasions, I have accidentally switched the Makita (Dolmar) off due to the switch sticking out while I've never experienced this with the Solo. The air filter and housing is much larger on the Solo, offering superior filtering capabilities. I did install the HD kit on the Makita, but removed it since I mainly cut green wood and the design of the filter makes tuning the saw much more difficult (at least for me). Lastly, the chain adjuster on the Solo is housed in the case, not in the cover as in the Makita/Dolmar. I find mounting bars on the Solo is easier and the adjuster may even offer more adjustment over the Makita. My Solo is also more powerful than my Makita.
So, what do I think about the 681? It offers exceptional performance, excellent reliability, in a very refined packaged. I would highly recommend it. I usually use the Makita for limbing and the Solo for felling and bucking. If I had to pick one, I would choose the Solo, it simply seems better in terms of quality and performance. Btw, you can purchase Solo parts online through Solo or call Bailey's. Most Makita/Dolmar parts interchange with Solo's so you have a few more options available to you. Lastly, check out Andyshine77 video on how to properly tune the saw.
Enjoy your new saw.
