Canon Imagemixer 3 vs Final Mate-Trim with GOP Accurate vs Split/Cut with Frame Accurate

I recently bought a Canon HF S100 for my vacation and brought along my laptop, ACER 6930, Windows Vista. The camera is awesome, good AVCHD HD camera. I have it set to record in 24 FPS Cine mode at 24 MPS (1900x1080 lines?? ). The video format is in H.264 Streaming and MTS File. I have been downloading to this computer for the past 8 days. My goal is to edit these vacation videos.
I have installed the imagemixer 3 Se Vers.3.3.0 coming with the camcorder in the box. Everything worked fine until I tried (following step by step the handbook) in the video editor to trim the videos by clicking In and Out button, the output trimmed files are not played exactly what I cut in imagemixer 3 Se, I lost the important image I desired to get, and the audio doesn't seem to play. I known that all software coming with the camcorders are not worked very well for camcorder videos, like HD writer, Sony PMB, etc, is Imagemixer also a bad editing program as people said? I think maybe it is.

Nowadays, I have searched online to get a canon HF S100 editors for simply dividing and merging, I found Aunsoft Final Mate, which is claimed as “Frame by Frame Cutting lets you get exactly what you see”. I just downloaded and followed the smart camcorder wizard to capture my files from S100, then drag and drop them into timeline, click Vernier to locate timepoint and tap Previous Frame & Next Frame to get the image I want, now click Split to cut files into two, delete the one I don’t want, after repeated some times, I just export my merged one file without conversion, and the output file can be played beautifully on PC. Most importantly, I got what I desired.

After this experience, I found some info about the dividing/cutting ways of both program: Imagemixer 3 and Final Mate. Imagemixer 3 provides GOP Frame Accurate trimming, while Final Mate provides both GOP Frame Accurate and Frame Accurate splitting/dividing/cutting.

The Differences between Imagemixer 3 GOP Accurate and Final Mate Frame Accurate:
1. GOP Accurate: GOP stands for "Group of Pictures". When your video is encoded and compressed into an MPEG format, each frame becomes part of a group of pictures. The first frame of that group is called an I-Frame (also called keyframe by some) and while its compressed, the original material can be reconstructed from the data in the frame. The rest of the frames in the GOP are difference frames. They are coded with the difference between the I-Frame picture and the current picture. That way only the material that changes from frame to frame needs to be re-encoded. You cannot reconstruct the frames in the GOP without first processing the I-Frame and the previous difference frames. A GOP is usually 15 frames, but that's just a convention its can be any number of frames (DVD limits GOPs to 18 frames). In the US, which broadcasts at 30 FPS (29.97 actually) a GOP is 0.5 seconds of video.
When you use Imagemixer 3 in GOP mode, all cut points will be rounded to the next GOP boundary. So you will find output files’ starting point is not exactly what your want .

2. Frame Accurate: HD recordings from camcorder are often highly compressed before stored, such a compressed movie contains key frames (I-frame) and non-key frames (B-frame or P-frame). Key frames can be displayed independently, while non-key frames can not be displayed without key frames. So the functionality to seek and display each frame correctly, no matter key frame or non-key frame, is called frame accurate (frame by frame). (Tip: Frame is one of the many single photographic images in a video.)
With Frame Accurate mode in Aunsoft Final Mate, the cut point will be on the exact frame you specify.

When to use GOP Accurate Mode or Frame Accurate Mode?
Because a GOP of MPEG2 may have 15~30 frames each, but an AVCHD GOP could be seconds in duration. So, simply cut on the GOP boundary may lead to a miss of several seconds, that would be not acceptable for many users. Hard to imagine, when a user defined a cut point on the time line, but the output is 3 seconds away from that point. So, in this situation, users have to select Frame Accurate Mode to get what they see. If you don’t care about this, or just for edit file for pleasure, you can select GOP Accurate Mode, because it is fast in encoding than frame Frame Accurate Mode.