Abraxas
Explorer
In theory you should still check even if you don't want to use it this round. But if you forget about it, nothing bad happens; you just roll for recharge on its next turn. That's completely different from forgetting which round the breath weapon recharges. The 4e way is somewhat more resilient to sloppy DMing.
Not really - if you forget to roll the recharge on round 4 or 5 and then do roll the check and fail to get a 5 or 6 on the die in round 6 - you don't get to use the ability. If you forget to mark off a round on round 4 or 5 with the 1d4 rounds between method you know you get to use it on round 6.