1 - The DSTwo has lasted the DSi and 3DS with no new models needed.Ah, gotcha
We went from 1.0 to now 6.2 in 2.5 years. I was looking at R4i Gold 3DS site and it looks like they were able to patch up all revisions since 3DS software 4.0ish? Even on older cards? Thats about a year of patches. I presume that they also got better at hiding the card from Nintendo (they had to right? since the blocking makes Nintendo's grip tighter and tighter).
Hopefully current ones last until the end of times with just software patches.
But even if it doesnt DSTwo is like 3 times the price of R4's, so getting a new R4 every few years could be a strategy with equal budget, but you do end up with several cards that you can use on DSi and DSL long after they have been stopped on 3DS. It also may be a smarter strategy, because DSTwo cant survive forever? So dropping 15$ and having something work without the need to buy anything else for a year or two may be better than hoping that hardware made 3 or 4 or 5 years before works. You know what I mean? Its not like DSTwo hasnt been blocked before, 4.x blocked it, 5.x blocked it, this 6.2 blocked it, its just they have always been able to fix it via a patch, how long is that going to last though? Maybe forever, maybe not... and who knows maybe R4i gold 3ds hardware is at that point now too...
Either way I am impressed by the team's support of these cards, I remember the early days of DSLite carts, it would take months to get anything (when new games wouldnt run).
2 - The R4i Gold I was sent for the official GBATemp review was a revision 6, whereas they're up to multiple "Revision C" models now (which itself is an issue, there's some labeled C that can update, and some that can't).
Given the track record, assuming that the R4i Gold can outlast the DSTwo, even in theory, is just wishful thinking. The DSTwo does not use the same update and booting methods are other flash carts. Other cart makers are aware of this, they just purposely choose not to go that route because it would cost them more to make, thus cutting into their profit.
Even if you estimate that the number of replacement R4i Gold models you'd need to count for one DSTwo would cost the same or less... it's like counting the number of replacement cars you'd need if you bought the cheap model. If you even need to do that math, it's an indicator that there's something wrong with this decision.
That said, there's also shipping costs and shipping times to worry about, etc.
If you plan on updating your 3DS on a regular basis, the DSTwo has the best record. If you don't, the R4i Gold is a great budget model.