Here is a comparison of the two speakers. You can see the difference between the magnets. The stock tweeters that came out of my 2003 Subaru Forester actually aren't bad. The magnet size of the tweeter is about the same size as the woofer (mid).
Here is a front view.
The hole size was not 6 1/2. I had to build spacers to get them to fit. I had some extra wood laying around so I just used it. Not that pretty but I thought it would work and it did some what. I got it all back together and rolled down the window and it hit something. Come to find out the window was hitting the back of the speaker. It needed to come out another 1/2 in. I took it all back apart and came up with an idea to space the top of the speaker out 1/2 in and the bottom 1/8 in. I did this with card board. I catch two spacers that match the wood spacer and folded once in half to get the space on the top then used the second as normal. Seemed to work as expected. The window doesn't hang up on the speaker any more.
This is before I put the extra card board spacer.
Does it sound better? Oh yes. I am every pleased with the sound quality is way better and the control of the sound is great. I am powering them off my Pioneer AVIC-D3 which doesn't have enough power to really push the speakers. But over all it sounds great with the JL 10W7 pushed by a soundstorm 1500W D Class Amp. I have an old rockford fosgate punch 60 amp that may through in to push these but I haven't decided yet.