Hi, here are some avchd video editor resommended by cnet software reviewer. and sorry for no link involved (poor reputation and low contribution)
And before you give them a try or estimation, i suggest you give some alternative solution a try. since compare to another hd video format, mkv, AVCHD video is not open source project. it means even the avchd video editor developers need pay high price on it. that is the reason you overdraft for a avchd editor. try to convert avchd m2ts to mkv format, then with proper mkv codec packs installed on your XPS 420, you can edit your avchd recording footage effortlessly.
draw my source from: http://www.winxdvd.com/resource/convert-m2ts-to-mkv.htm
And here is the list for you:
Added 5/6/08: CyberLink PowerDirector 7 Ultra. $119.95; no trial download.
Added 11/15/07: Final Cut Express 4. $199; no trial download. For Intel-based Macs only. As far as I can tell, there's no list of supported models, which bodes well in my mind. Notably, FCE4 can mix HD and SD video on a single timeline, just like its very expensive big brother.
Updated 5/14/08: Sony Vegas Video Movie Studio Platinum Edition. $129.95; 30-day trial download. As of Version 8.0c, Vegas Platinum supports Panasonic and Canon files. I opened a few files to check. Woo hoo! According to the release notes for Version 8.0d, it now supports 1,920x1,080 files, but not for Panasonic.
Updated 6/6/08: Pinnacle Studio Plus 12. $100; no trial download available.
Final Cut Pro 6. $1,299 (part of Final Cut Studio 2); no trial download available, and AVCHD editing requires a Mac Pro with Intel Xeon CPU.
Updated 4/2/2008: Corel Ulead VideoStudio 11.5. $99.99; The current version of VideoStudio now lets you import AVCHD files--it no longer requires the entire directory structure--and author AVCHD discs.
Apple iMovie '08. Apple only supports a few of AVCHD camcorders, however, and even those have a couple of caveats. Here's the current list of supported models.