I'd think it unlikely anyone's got both!

well yeah
my wife's cousin's husband

has an acer that looks very similar, dunno if it is the exact same model though, anyway, after looking at the spec on techradar, the 5536 has more 'stuff' (sd card reader, hdmi, an extra usb, express card slot/port are NOT on my Lenovo). The main thing for me with his Acer is the fact that I (and the owner) both despise the touchpad. Have a look at one in PC World- there are a few Acer models with the same design, the touchpad is a dip in the plastic chassis rather than a hole that has a touchpad unit inserted into it
(like this) You really need to go and try one to see if it'd suit you, or not. I much prefer the Lenovo keyboard too.
It depends whcih you're looking at -post the spec up here or a link and we'll all berate it for you!

The main comment that stuck in my mind about ACER from this board was someone with a 6 week old machine that had died and the response was along the lines of 'well what do you expect - its an Acer'
That really put me off - probably without good reason - but I crossed them off my list. I am skint therefore build quality and the OS lasting longer was important to me. Therefore Lenovo, Win7 and a dual core of some description were important for me. I write mainly, don;t game or use photoshop etc so graphics cards are not important, neither was hdmi. I used a few Lenovo machines and liked the keyboard so I ordered one.
The reviews I've seen of the Acer all have Athlon x2 processors - dunno if they compare well to the PDC in the Lenovo - bigger brains need to answer that. They have all had Vista in some form too - dunno whether that is a concern for you or not. But, isn't Vista more of a power hog?, again, bigger brains along soon I imagine.
And, the lenovo battery life has been consistently over 4 hours in tests with wifi use - the reviews of the 5536 I've googled state 3hrs or under in the main. Again, is that important to you?
AND, replacement batreries, from Lenovo, official ones, are approx £80 for this laptop - unlike my wifes £300 Dell where a battery was over £140 from Dell!
Look into that - batteries degrade and are considered consumables by the manufacturer. Also, cheapo Chinese etc replacements can be dodgy, so cheaper replacements (or spares for 8 hours use in the library) was important to me in the long run.
I do miss not having an sd card slot but I use that once or twice a week for 10 minutes ata time, so a 99p adapter ain't a hardship. I never use three usb ports at once never mind four.
Just go to PC World and ask to use an Acer with the same touchpad and keyboard as the one in the piccy above - if you hate using that in the shop, it'll grate on you every time you use yours at home/work I reckon.
I hope that was some use. Mike likes his Acer, just not the touchpad. This is his first laptop and was using Win98 and XP before this in his loft based desktop. He is still giddy with excitement over having WiFi and a hard drive that is greater in number than his age.
pip pip