I'm still playing Fusion as well, haven't gotten too far, just entered Sector 2 for the first time...
As for the trilogy, I may buy it, just for aesthetics because I liked the feel that the Wiimote brought to the series. I still have all three in their original mediums, beat Prime 3 100% for Normal and Veteran, working on Hypermode currently, holding off on Metroid Prime and the Emperor Ing until I can find a straightforward guide on the few pickups (less than 5 each) that I'm missing.
I started with three because I couldn't find any other in the Metroid series (locally, as a whole) and my friend would not shut up until I got one.
My experience of the storyline didn't suffer because of that because as I've seen, read, and been told countless times by my same friend, the games are not released in chronological order... (Zero Mission/Original Metroid are first, then the Primes, afterwards it's Super Metroid, and Fusion is the last [so far])
Can't wait for Other M...