I've said it before and I'll say it again: these slot 1 solutions won't be useful until Nintendo starts making more use of the slot 2 port for hardware expansions.
Until that time, slot 1 solutions provide no significant benefit over slot 2 solutions while forcing users to endure significant downsides (namely no GBA support).
Well its not just a Slot 1 advantage. It's much more than that. It's not having to flash the firmware to get your games working. It's not having to patch a rom everytime a new game comes out. It's the battery life thats spared and prolonged. Since many of you already have a Slot 2 card for GBA games, I guess the main reason any of you would think to buy this cart is for the No flashing, No patching, and battery life pros that it carries.
I have an old F2A cart for my GBA. Ill play my GBA games on that and leave the NDS for NDS games.
Technically you don't have to flash the firmware if you use a Passcard while playing. That's already an option for those who choose not to FlashMe. I've already flashed my DSlite so no going back for me, even if I wanted to. Besides, I prefer the added security of FlashMe.
No patching? I don't have a problem with patching. It works seemlessly for my G6lite. Makes me nice little .sav files too! I realise that sometimes it takes a while to get new games patched up to work right. Okay. Score one point for DSXtreme if all games are 100% compatible immediately after release. However, I find the vast majority of games work immediatly upon release with my G6lite, anyways.
Battery power? More would be nice. Period. Score another point for DSXtreme.
So here is the break-down of the DSXtreme (vs. GBA slot flashcarts).
Pros:
1. No patching required means instant playing of newly released ROMs
2. Prolonged battery life of DS
3. Built-in USB
4. Use of slot 2 peripherals in conjunction with DS games
Cons:
1. Higher cost
2. No GBA
Is incompatibility with thousands of GBA games a worthwhile tradeoff for the above pros? Perhaps if you already own a Slot 2 flashcart and don't need this function. But if you are in this boat then the question becomes, do the above pros make it worthwhile to drop CAD$140(+ship) on a second flash cart? For me, the value just isn't there yet. The bottom line is it just doesn't enchance play experience by a significant amount. Does it add a few nice features to NDS-only gaming? Yes. But is it overall more useful than a Slot 2 flashcart? I highly doubt it.
Will it ever become more useful? Well, that depends on several factors:
1. The quality/quanity of homebrew support and development
2. Future hardware applications of the Slot 2 in conjunction with NDS games/applications
3. If someone can make a GBA emulator run off this cart
Really, significant advancement in factor 2 is the only thing that would push this cart above and beyond the current Slot 2 competition since factors 1 and 3 are likely to be "equal to Slot 2 solution" at best.