I know I struggled last year the whole Rupes v BOSS choice and even after reading everything I could find on the subject ya just never know until you yourself actually drive `em both. When at Barret-Jackson in Scottsdale last January, I got to play with a G21 in the Griots tent for a bit and it was enough to pique my curiosity enough to look into grabbing a G21 at some point.

Normally when time is of the essence and some compounding needs to be done, the Flex 3401, M101 on gray LC Force pads takes care of things like an old beat up van in a relatively expedient manner, although I`ve also used Rupes 15 Mk2 with billet backing plate on these types of vehicles as well. The G21 with 6.5" BOSS Microfiber pads and Megs D300 ate this thing up even quicker than the Flex and far less taxing; 4 passes and move to next section. I`m quite impressed with this machine and really look forward to using it again.

i think the ergonomics of it vs the Rupes (in my case) makes it much easier to use than the Rupes, although the Rupes is still noticeably smoother for the most part and feels more solid/monolithic. The G21 kinda sorta feels more `assembled` if that makes any sense, but is still very smooth and comfortable to use; it`s slightly more compact compared to the Rupes and the angle of the handle and more rounded rubber grips keep me from teeter-tottering the machine/pad as much, eliminating some measure of stalling.

Even though it`s a relatively flat vehicle in this case (Ford E250 panel vsn), and ideal for a 21mm stroke, there are still a few curves over the wheels and some recessed body accent lines that require more attention with the Rupes as opposed to the Flex, and the G21 took care of those with ease, hardly any stalling and quite willing to have the pad edge pushed into recesses to polish. While not apples to apples (21mm v 15mm) it`s become obvious that each has pluses and minuses compared to the other, mostly very minor things.

Regardless, anybody who dismisses the BOSS machines without having tried em, or disparages them as cheap Chinese knockoffs should probably rethink that narrow-minded view. The BOSS is certainly a solid piece of kit, worthy of consideration. Looking forward to trying in a more curvaceous vehicle to see if my current impressions hold. It`s a more comfortable machine to hold (for me) than the Rupes, with more rounded edges and rubber grips/inserts.

I did follow up on the hood with a yellow BOSS Pad and Scholl S40 and it worked very nicely and quickly; that extra 6mm of throw over a 15mm machine really covers a lot of ground efficiently.

As for a few more thoughts on BOSS v. Rupes,

What I prefer w the BOSS:
1. Variable speed trigger. Much more preferable to me, very easy to set working speed and then use variable speed trigger to slowly spread polish initially and then move right up to working speed without having to adjust speed dial. A little item but when you consider how often you do this at the start of each section,` it`s a more convenient approach than Rupes slow start.

2. Ergonomics. For me, BOSS is more comfortable to hold with its softer rubber grips here and there, bit more compact and rounded chassis as well. It just seems to rest in my hands in a more natural manner. Rupes is a bit more `square-ish` with regards to chassis.

3. Usage/effectiveness/learning curve. The BOSS just seemed to be easier to use effectively right outta the box. While it has a more powerful motor, spec-wise, than the Rupes, I`m not sure how (or if) that translates into more torque, thus less stalling.

I didn`t use any if the included washers to space the plate a bit off of the shroud for 100% free spinning and I`m not sure I will. The Rupes seems to have more shroud to plate drag/contact in its stock configuration as when cleanng/spinning` a microfiber pad with compressed air on the Rupes, the stock set up does not allow the pad to spin while compressed air is blown on pad. The G21 will spin while being blown off for effective pad cleaning. There is still some contact with the G21 as when pad stops spinning when power is switched off, it does not completely spin freely until momentum stops it; the last little bit of rotation stops in a manner which indicates friction is involved in the final stopping rather than loss of momentum.

What I prefer w the Rupes:
1. It`s a Rupes. For me, anyway, with the Rupes being the original long throw,` there`s just a certain mystique` (well warranted)` about their machines. The user experience with the Rupes is a very relaxing, almost artistic experience once you get your technique dialed in, which I still have yet to completely do; getting there but still a ways to go.

2. Smooth and soothing while in use. The Rupes still has an advantage in overall smoothness, especially with a billet backing plate bolted on and a yellow or white Rupes pad on it. It`s a combo that just makes me want to polish something for the sake of using it and enjoying the feel. The sound level of the Rupes is smooth as well, a consistent soothing `hum of quality`; G21 is a more mechanical sound although in no way objectionable

3. Rupes has 25ft cord option, not avaliable on G21 that I saw. Minor inconvenience at most but worthy of note.

Pretty much right after ordering the G21 I was on the fence regarding if it was dumb or not, being only an occasional hobbyist with the Rupes 15 and the Flex 3401 on the shelf already; after using it for a few hours, I have no regrets in buying and trying the G21, that`s for sure.

Now the Duetto I picked up last holiday season, that`s turning out to be a dumb purchase...have used it for about 15 minutes so far. With a Rupes Mini, LHR15, Flex 3401 and now G21 I just can`t think of a situation where I might find it useful. Oops.

G21 & LHR15 Mk2 side by side: