Hi Icchan, sorry for the late reply.
Yes, the W1100 would have a significant 1 leg up in the lumen division. Think about it. Although manufacturer's inflate ANSI lumen numbers, you're talking about 700 difference on box specs.
The HC4000 is a great projector no doubt, but it's great in a HT room, where it's dark and you can benefit greatly out of its superior black levels. However, if you like to operate in a more lit environment or like a lit environment such as myself when it comes to sports night and what not, the HC4000 may not be your fit. You'll need a brighter projector. The W1100 is considered one of the brighter entry level 1080p projectors. BenQ has always been known to deliver brighter than average projectors. Also you still get a 4x color wheel, high contrast ratio. Read Coderguy's review, he calls the W1100 the sharpest projector. Sharper than HC4000. It'd be great for games & sports. It's got onboard speakers if you ever want to make it portable or bring it to a friends house.
However, if you're planning to fix your projector and leave it on a mount and have a very well light controlled environment (dark) and mostly use it for movies. I would honestly suggest you to go with the HC4000. However if you're into other areas, and like a lit environment, W1100 for sure!
However, best bet would be to purchase from a retailer or online store with easy returns, no restocking fee, and they carry both models so you could always return one if you realize it's not a fit for you.
I Love Apple, BenQ, Samsung, and Acer Products = )