Only had expirence with the 2731(7 1/4 Fuel) I'll start by saying The reviews online are accurate and pretty good depictions of the tool!! On to my short review.. I bought off CPO Tool and got the 2731-21..Paid $320 total Comes with saw, 4ah battery, m18/m12 charger & carry bag.. This thing is a beast..definitely replaces a corded saw!! I use it to cut everything..hard wood, soft wood, treated, not treated..the run time from a 4ah battery and brushless motor is substantial enough to handle a light to medium work load..With 2 batteries and your cutting all day!! The only time it bogs is if you push a high tooth blade too fast or don't keep a straight hand..much like any corded saw will do if it's over worked (but those are user errors) The saw has the same feature like other Milwaukee tools that will cut power if it's really over powered..You really have to dog this thing to get it to cut power..but reset in a second and it's ready to go again!! I've had it about 8 months getting medium to heavy use day in and day out and it's always ready Togo!! The only time the corded one gets used is when I won't let someone use it who I know doesn't care for tools the way I do haha Overall this gets a very high rating from me and I will recommend to anyone!! I've not used the smaller FUEL saw but it has great online reviews and I'm sure it's jus as strong as the full size!!