Dell XPS12 comes with 4th Generation Intel Core i5 processor and is paced with 4 GB of DDR3 RAM that gives stunning performance while playing games, browsing web or playing HD content. Currently I am also using this product and really i'm happy with it http://amzn.to/1Hjsk9L

If I want to upgrade 256Gb SSD in the future. I want to know what considerations do I need to have.
I have an XPS 12 9Q33, i7 with 8Gb RAM and (SSD) mSATA  256GB.

Yea let me tell you about the Dell Xps 12 9Q23. I have had nothing but problems from day one of owning it. I love the design and suits my lifestyle perfectly. But the screen and touch freeze constantly and you will find that right in the middle of working on something you will have to restart the whole tablet. And shortly after using it you will notice burn-in on the screen. I already had the hard drive fail after only six months and although Dell has finally admitted that the Dell Xps 12 has burn-in screen issues and they will replace for free, but then again I will be without a computer for at least a month to month in a half. This tablet has many issues.

I agree with the other user. Notebookcheck needs to update this review to reflect this issue and bring attention to it.

My XPS 12 along with many others - possibly every XPS 12 - experiences image retention issues. DELL has been tight lipped about any possible recall or update to the broken screen so buyers beware. Until they replace the screens in these units with working ones i cannot recommend this.

There are major issues with the screen of this laptop, both the xps 12 9q23 and the newer 9q33 are both effected by image persistence/image ghosting. It may not become apparent right away but virtually every machines have this fault because of the LG screens they are using. Don't buy until there is a recall or it has been corrected!!!!!!!
http://en.community.dell.com/support-forums/laptop/f/3518/t/19497269.aspx

I have this XPS 12, and the one thing you will have to get use to is lots of adapters.  Want to plug in a monitor?  Pull out the mini display adapter.  Want to plug in a memory card?  Need a USB adapter for that.  Want to plug in an Ethernet cable?  Look for an adapter.  DVD player?  Look for the USB external DVD player.  Oh, and none of these adapters are included.  So start shopping accessories ahead of time so you are ready when you need that adapter.

Where can i buy dell xps 12 with i7-4650u processor?

Thanks TAC, I updated that.  Appreciate the kind comments everyone!

To answer the question regarding use with a stylus, it is my understanding that any device with a capacitive touchscreen can be used with the proper type of stylus. E.g.:

http://www.amazon.com/BoxWave-EverTouch-Capacitive-iPad-Stylus/dp/B000BUI76S

I hope this helps!

Thank you, it's a very well explained article. Does it work well with a stylizer (pen)? Is there any other ultrabook that can support a stylizer?

This laptop doesn't include a Card Reader: SD/MMC

Great article and analyses on the Dell XPS 12