My story goes back to...2006. I had had my DS Phat for a year, always with two games: Nintendogs and Megaman 5 DS. They were good, but I craved for something new (this was WAY before I discovered GBATemp). I had no GBA flashcart, and I got through the glory years of that playing on an emulator I really cherish (Visualboy Advance). Only games I really bought were GS2 (COS THAT LYK DA BOMB), Mario Kart, Pokemans, etc...
Anyways, back to my story. I was searching on Google after seeing some stuff about getting games for free on the DS, and this was just when the start of the slot-1's were coming through...so G6's and M3's were really popular back then + passmes and all that. I stumbled upon the ONLY flashcart that was slot-1 at the time: the DS-X. Sure, it was flipping expensive (108 euros) but totally worth it when I got it like 3 days after Xmas.
I loaded up ANY game, it would boot and play wonderfully. The menus were awesome, the loading was decent, it was FREE games for God's sake.
BUT...the downfall of the DS-X was really 1.1.2. After that, they never were the same. 1.1.0 was the best era, I played any game without patching, etc...just trim and go. It lasted me like...6 months before they starting going AWOL on users and I said "screw these guys, I'm gonna buy a new cart". I got lucky my sis bought a DS at that time (ironically, her DS just broke the other day), and I ordered the R4 from DX (got to know that site). After that, I got the R4 for me, and the DS-X I gave it to her.
She was happy, so that's what mattered. And compared to my old DS-X, the R4 was awesome. FINALLY no crappy internal memory, I thought. And Pokesav worked for the first time ever without having to convert like 50 times. This was shortly after I discovered GBATemp (I discovered it from a thread on the US release of Pokemon Diamond, actually).
The R4 lasted a long while, until it started failing to play the latest games...so I then ordered a DSTT, which is my actual flashcart nowadays, with 4 GB mem. MicroSD. I simply love it. YSMenu plays all I want (with some fixes, but eh...it works now), so I'm happy. The R4 I gave to my sis, cos the DS-X sucked right now, and was put on a shelf to gather dust.
I've had three flashcarts pass through my hands, and I must say the DSTT/R4 were the best. DS-X was good initally, but internal memory issues (once it literally died on me, I had to use their fixer stuff, which made me reinstall XP, etc...) and tons of hours lost trying to revive it made it a crappy cart in the end. It was worth the investment at the time, but now I wouldn't even dream of buying it. It had so much potential, my God...if they had invested well, it could still be the most powerful cart on the market today.
Oh well...I'm glad to say, though, that ALL 3 carts still work like they did on the first day they arrived. The DS-X just has crappy firmware, is all.