I'm a bit late to the party, but figured I'd add my thoughts on this machine, in case someone stumbles upon this thread that's looking into buying this.
The Igen2500 is a good machine. I had to return my first one because it leaked fuel and had other issues right out of the box. The second one has been solid so far.
Pros:
Super quiet
Does 2000W faithfully. Anything more than that and it sounds too strained.
Front panel is it's best feature -- fuel remaining (in liters), power output, time left on fuel, built in hour meter, etc. is absolutely priceless and I've not been able to find a comparable generator with these features.
Reliable so far. I've used it for a few hours straight in 90+F temps, and 0-10F temps. Generator doesn't care and always runs and puts out power.
[I've only got about 20 hours on it, so this is far from a long-term review]
Cons:
Does not ramp up quickly enough, even with ECO disabled; performs poorly at peak/starting loads. I'll elaborate:
I tried running my 32' fifth wheel air conditioner off it. Doesn't have enough giddyup to get it started. I've had no trouble with other smaller inverter generators, Honda 2200 comes to mind. With the Westinghouse it will struggle and trip the breaker. If you're insistent/patient you can reset the breaker two or three times quickly, and the A/C will eventually start, but probably not good on the starting capacitor/AC unit. Once the AC is started, at that point it's a normal 1400W load that the generator handles fine-- until the AC thermostat shuts it off and wants to restart again. I think the 2500W starting rating is dubious at best.
It won't run my portable welder, which is a HF Unlimited 200. Even if I turn the settings down quite a bit (running tiny wire at low speed/volts), the generator just won't react quick enough and will produce a fault on the welder. I know for a fact this welder is not drawing anywhere near 2000 running / 2500 starting watts at the settings I'm using. Just poor circuitry in the generator that can't handle sudden loads is the only thing I can chalk this up to. Again, a Honda 2200 inverter generator runs this welder, even with the welder turned up to max (for 120V). My Westinghouse Wgen9500 generator also has no trouble with this welder, using 240V input at max settings, which is somewhere near 8 KW of power demand.
If let set for long periods (3+ months) it can be stubborn to start. I make it a point to run it every couple months at least, and it's not been too much trouble, usually 3-5 pulls gets it going.
Conclusion:
I basically purchased this for long duration power outages where I might have to run my fridge/freezer and other low(er) power gadgets for long periods. My larger generator would eat me alive in fuel costs if I were to try to run it for days on end. I suspect the IGen2500 will work fine for this purpose. I also wanted something portable I could take on camping trips, or even to distant places on the property where I don't want to drag an electrical cord to. For $450, I think I got my money's worth.
If getting my A/C unit and/or welder to work with it was crucial (it's not), I'd pony up for a Honda or something higher quality.