This question can only be answered by yourself. The difference is the Pokémon that appears at certain places and at wich rate. It depends of what Pokémon you want to catch.
Pokemon Heartgold and Soulsilver are the remakes of the old Pokemon Gold, Silver, and Crystal series. Pokemon Heartgold and Soulsilver are for the Nintendo DS.
soulsilver and heartgold, it has the most trainers
No, there are no underwater routes in Pokemon HeartGold or SoulSilver. The HM Dive is not available in Pokemon HeartGold or SoulSilver.
he is not in Pokemon soulsilver or Pokemon heartgold
SOulsilver
That is impossible in Pokemon HeartGold and SoulSilver.
You can only go to Johto and Kanto in Pokemon Heartgold and Soulsilver
Pokemon Soulsilver and Heartgold cost about 35 to 40 dollars on the US
The card key in Pokemon Heartgold and Soulsilver is located in the Goldenrod Underground.
The Quick claw is located in the National Park in Pokemon Heartgold and Soulsilver.
You can't. You need to get Heatran from Pokemon Diamond, Pearl and Platinum and then trade to heartgold and soulsilver.
Suicune is at Level 40 in HeartGold and SoulSilver.