Too heavy?? Well, it might be an ounce heavier. Generally it is comparable to any white gas stove on the market after a week of running it. It is lighter than Alcohol and canisters at about two weeks. It runs at about 3x the efficiency of a Whisperlite. Someone said it has a 5.2oz fuel tank. You should NEVER fill it that full or you won't get it to run very well. Fills should be done to the bottom of the fill cap while level. Otherwise expansion, due to heating, may be too touchy to regulate properly. It makes for a very noisy stove. Even the manufacturer says it is a 4oz tank. Since it eliminates the pump, and associated mechanism, there is only 3 moving parts: valve, cleaning needle and fill cap. Very low maintenence with high reliability.
Specs from Optimus:
Average boil time for 1 L of water
~ 7 min/1 l water, depending on climate, altitude etc.
Average burn time
up to 50 min on one filling (0.12 L/4 fl. oz) at maximum output
10 x 13
3.9 x 5.1
Note that the weight includes a ~2.5oz cup.
I have tried many stoves, commercial stoves and home made ones. Tuning is important on a SVEA. I use a ~40 year old 123r. It has a self cleaning needle so it maintains a clean jet under most conditions. Maybe a teaspoon full of sand in it could clog it, but it does not clog up easily.
For winter use it totally depends on the size of the group. For one or two people, it is perfect. Back in the 70's we used it for ice fishing in our little pup tent shelter (Covered with a sheet of plastic.) We could hold 50F with it on med/low at temps of -10F. It would burn about three-four hours on low. My brother and I would typically drink hot coffee laced with Drambui from snow melt since we were often too lazy to hike a 100yards to the nearest hole to get water.
The pumps are almost manditory in temps much below 20F. Though, a double prime works to get them going. It helps to put a pad under them. On HIGH, you get about 8L per 4oz. On low, you get about double that.
Depending on how many people (I had a family of four) it can be a bit too small. But I have cooked breakfast (bacon, eggs, and fried bread, in lieu of toast.) It will handle a 12" frying pan full of trout, but the flame spread is fairly narrow. An 8" pan works better.
You can adjust the flame from around ~500BTU to ~4700BTU. Simmering and cooking are fairly easy with this stove. It makes an excellent heat source for simmering.