I am having the same issues after 2 months of ownership. I will probably start with low lying fruits like the trans oil and if that doesn't work try the adjustments in the video. Tried out jbarone's ssp in one of his MS3's and it does feel way better, so that's a must have IMO.
Then try adjusting your shifter, as I've recommended here in the past. Here's a common vid on the subject:
The shifter linkage adjustment made a big difference for me. I drove my car for about a year and always had some trouble between 1st and 3rd. One tooth on the linkage and it was like I had a totally different tranny.