RRSP can be a bad idea for people who will not contribute to the consistently. Say you are able to put away only about $70,000 by the time you retire. Chances are it took effort to save that money but by the time you start withdrawing you will only be recieving a small amount per year. Where it can hurt people is if they have income tested benefits from the government. They say recieve $2000 from their RRSP, are then taxed on that amount but the kicker is they can lose possibly thousands in drug benefits, OAS, and housing assistance.
Basically if you can only put $50 a month away for 30 years you would be better of keeping that money and invest it in something like education so you can make more money. Or just spend it as it will give you more now while not really taking away from your future. If can put away more than that RRSP are great.
Oh and the Home Buyers Plan Limit has been upped to $25,000. If you have a spouse with an RRSP thats $50,000 for a downpayment. That is a great way to pay for the house. If only buying a house wasn't such a bad investment then it would be an even better idea.
A good strategy is to invest both in the RRSP and the TFSA. When you retire, pull the money first from the TFSA. It will not count as an income so you will get full OAS.