Former Ireland fly-half Tony Ward says coach Joe Schmidt has assembled the "strongest Irish squad ever to go to a World Cup" for the tournament in Japan.
Ireland will bid to progress beyond the quarter-finals for the first time.
"There is no question this is a much stronger squad than in 2015 with real quality cover in every position," said Ward.
"When Joe names his 23, the eight in reserve are almost all impact players who can make a difference."
He added: "There are grounds for optimism."
Ireland fell to Argentina at the last-eight stage of the 2015 World Cup after a number of key players were ruled out by injuries during the competition.
Since then Schmidt has set about increasing the depth of his squad and when his 31-man panel was announced last Monday, long-serving second row Devin Toner was among a number of big names missing.
A comprehensive defeat by England in a World Cup warm-up game on 24 August was followed up by back-to-back preparation victories over Grand Slam Six Nations champions Wales in Cardiff and Dublin over the last two weeks.
"I think we are in a good place now despite what happened at Twickenham a fortnight ago," 19-times capped Ireland international Ward told BBC Radio Ulster.
"That dampened public expectation but the appetite has been whetted again by the performances which have seen us beat the Grand Slam champions twice in a week.
"Given what we witnessed at Twickenham though our optimism has to be very guarded but that is no bad thing."
'Malfunctioning line-out and wrong decision'
Saturday's game at Aviva Stadium marked captain Rory Best's final appearance for Ireland in Dublin, and also Schmidt's last home game in charge.
"The feeling towards Rory Best and the pride people take in the manner in which he has captained Ireland is immense," added Ward.
"For me he's under pressure from the line-out, there's no doubt about that. It hasn't been functioning as Ireland would have liked.
"Hopefully it will be better in two weeks' time and for the rest of the World Cup but as a captain he is par excellence and invariably he makes the right calls.
"I think there is still a question mark over Jean Kleyn as he is going and Devin Toner is not. I think that was the wrong decision. The decision is made but that is my personal opinion.
"Joe has certainly tried to cover every possible angle, every permutation, and he has got a lovely dilemma to deal with in the middle of the field where he is spoiled for choice."
Sexton and Murray reunited
Fly-half Johnny Sexton played for the first time this season in Saturday's 19-10 win over Wales, while Conor Murray also started as Ireland's highly influential half-back pairing of recent years was reunited.
"I thought Sexton did ok. There was a lot of ring rust and a few uncharacteristic loose passes, while some of the kicks were a little loose too," said Ward.
"He'll be happy to get a game under his belt and is still of course very important for Ireland but Conor Murray was slightly the more impressive on Saturday for me.
"They are without doubt our best two half-backs but hopefully Joey Carbery will be back ready to play at 10 or 15.
"I've been really impressed with Jack Carty too and when you consider that John Cooney couldn't make the squad and you had Luke McGrath shading Kieran Marmion, which a bit like the Toner decision has been controversial to say the least, they are all positive factors for me.
"That is the quality of the competition in the Irish squad at this point in time."
Semi-final hopes 'hard to call'
Ireland, now number one in the IRB rankings, will begin their World Cup campaign against Scotland on 22 September, followed by their remaining Pool A fixtures against Japan, Russia and Samoa.
Southern hemisphere giants New Zealand or South Africa are their likely quarter-final opponents should they, as expected, progress from their pool.
"It's hard to call whether we can reach the semi-finals but I believe we are in with a real chance," continued Ward.
"Four years ago and at the previous World Cup we had a much more favourable draw but this is a tough one.
"I think the pool is OK - Scotland should be the hardest game with Japan probably the second most difficult match only six days later. Then it gets relatively easier against Russia and Samoa.
"Certainly when we get to the quarter-finals you are talking about the All Blacks or the Springboks and they don't come any more difficult than that.
"I would put England in that category too at this point but going into this competition, for me, New Zealand and South Africa are the two outstanding squads."