I am planning to buy one, but I heard strange stories as to how they handle MTS files

any experiences in importing editing and exporting with a mac pro laptop?

I use my 15" MacBookPro from time to time, but the internal HDD is not really up to the task of multiple video tracks on the timeline unless you are editing with something like ProRes 422 Proxy. You have the option of using external firewire drives for that though.

Using ProRes 422 LT is another option if you are not going to heavily load things.

Using regular ProRes 422 works with light loading of the timeline only.

It's likely that you are going to want an external HDD anyway, so don't skimp on that part.

Mac Pro or Mac Book Pro?

Hi I shoot with my canon HF11 at 1920x1080i 24mbs and transcode to pro res LT and it all works great with a macbook pro or my mac pro.

Quality is good too and you can see an example here: YouTube - British Beef Jerky Shoot 7-8-09 (http://www.youtube.com/watch?v=s1o1aE9OkHw)

There really isn't a strange story behind the handling of AVCHD footage - AVCHD footage is highly compressed and generally not terribly edit friendly.

On Log and Transfer into Final Cut (Express or Pro - which is how the footage needs to be imported, not attempting to import the mts/m2ts files directly - all files from the camera must remain in their original folder hierarchy) the footage is transcoded automatically into a more edit friendly codec (that being AIC on Express and ProRES on Pro). AIC or ProRES are both much more edit friendly, but on the down side they take a lot more space (between 3 - 10x as much space if not a bit more). Any current Mac with proper storage can edit that codec (as mentioned, either using a lower bitrate form of for example ProRES (LT) - if you're using the internal drive, which is really not recommended to use the OS drive for your edit/capture scratch drive; or get a firewire (or if you get a notebook that has an express slot and buy an eSata adapter, then an eSata) drive.

It sounds like you're looking at a laptop, but you mention a Mac Pro - the lines are very different. The Mac Pro is a tower system that is up to 8 physical CPU cores (in 2 quad core CPUs) that offers multiple expansion slots as well as 4 internal SATA drive bays and up to 2 internal super drives, currently max 32gig ram, etc. The MacBook Pro is the higher end Mac laptop which comes in screen sizes from 13"-17", 1x super drive, firewire 800, some models have an express card slot, some have a non-integrated GPU using dedicated video ram.

If you normally work with one single video track and up to 4 audio tracks in Apple's ProRes 422 down to AIC formats, any of the modern Mac will suffice, even the lowly Mac Mini. Also get yourself an external 7,200 rpm firewire drive or, better, a firewire dual RAID drive to use as the scratch disk.
If you work with multiple video and audio tracks such as in a multi-camera post production workflow or compositing effects, the Mac Pro tower is your only option.
Working with the AVCHD native files is not yet supported by the Mac.

There's nothing stopping you have lots of video and audio tracks on a lower spec machine, you'll just have to render the timeline.

But by the time you've added complex effects, shadows, keying, type etc, it'll have to be rendered anyway.

I've used my 2008 MacBook Pro (2.53 Ghz Intel Core Duo, 4 GB 1067 MHz DDR3 onto a LaCie Rugged) for editing AVCHD files (on admittedly basic, simple projects) with no problems at all.