Do u actually owned two of this phone and gave such comments?
I think a lot of peoples that choosing between this two phone might interested to know more but based on your comments you are actually misleading them.

I owned this two phones, let me give my personal experience of the actual usage of these phones, this is not another xxx vs xxx .

hold the phone also signal can drop
You must hold your phone in very odd way to see the signal drop, in fact when i do the test i need to use my whole palm to cover the back of the phone to see the signal drop, I believe you won't hold your phone by using your whole palm to cover the phone right?

battery life so bad
Not at all...in fact Sensation is at least on par if not better....(Sensation on stock rom vs SGS2 on  Villian 1.4)

fiz thing ppl see is the screen and sgs2 pwns sensation in that
In my personal experience, Higher resolution LCD in Sensation is much practical than SGS2  S.Amoled+, My phone usage is mainly reading news, web browsing, facebook, email, WhatsApp. On SGS2 Color is so vivid and contrast is very good but this didn't really help much when reading text in normal environment, on the other hand Sensation text is much sharper and can display more info in any single screen.

it's internal memory is only effing 1GB!  i install eternal legacy ad need 2gb la , even my old n96 got 16gb internal
I don't use my phone to watch movie, listen MP3 or play games so for me even just 1GB i will never able to fill up half of it, but generally the more the better, so in this case SGS2 is better but if I'm not mistaken the internal storage on SGS2 is only 2GB usable for App.

the camera picture colour so dam flushed
No doubt SGS2 is better in this area not matter front or back camera.

bootloader is locked, need to s-off s-on, so dam troublesome
Sensation can't even s-off at the moment. need to wait official release. but I won't think it will be  troublesome ....i think it's more troublesome to flash different rom everyday.

so conclusion sensation sucks
Really? I don't think so.
My other experiences of these 2 super phone:
- Overall SGS2 run more smoother then sensation, App launch faster in SGS2.
- Those who use email a lot..Control is much better in Sensation and it's faster than SGS2 Email client too.
- Contact Management is better in Sensation.
- SGS2 Browser is much smoother then Sensation
- HTC widget is better than SGS2.
- HTC Keyboard is better then SGS2. HTC keyboard can switch to chinese input without even need to switch the input method, in SGS2 need to download google pinyin. But always keep in mind a lot of other options in the market.
- Sense3 got more useful feature than TouchWiz4... a lot of peoples comparing the launcher part of these two customization but it actually consist more than that for example lock screen or even the way to u select text also consider part of the customization. So don't just compare the launcher part only.
- Sound quality is much better in SGS2.
- GPS accuracy in better in Sensation, tested with papago and google map.
- SGS2 feel good in hand, it's very light and so thin, Sensation also feel good in hand, very solid feel and the shape of the phone is just fit nicely in my hand, personally i prefer sensation.
- Sensation re-charge faster than SGS2
Some of my point I only mentioned in very general way, if you interested to know more in detail pls let me know.
I really like these 2 phones ...until this moment i still can't decide which to use as my primary phone.