Please excuse the tone of this reply - frustrated at the time of writing it.
The changes to non-concessional contributions are pending as a result of the recent Federal Budget. See
http://www.ato.gov.au/super/content.asp?doc=/content/60489.htm&page=4&H4
In addition, some of the comments I have read here regarding the recourse of the loans and tax benefits etc are too generalised, and some, simply wrong. I have spent a lot of time in this area, and received a lot of advice, which is certainly necessary for any one/SMSF looking at instalment warrant arragenements and taking advantage of 67(4a)of the SIS Act.
What the risks are for the SMSF and its members will very much depend on the SIS Act legislation, other tax legislation, the SMSF Trust, and how the Warrant Trust and relevant loan/security documents operate. There are other risks that have not even received any where near the required attention - such as section 295-550 of the Income Tax Assessment Act.
That said, nobody here has really dealt with the benefits of instalment warrant arragements succintly. Can a specialist compile a list?
I would urge most of you to be less "as a matter of fact" in relation to this topic.
Nonetheless, I don't want to put anyone off - there are numerous tangible and non-tangible benefits for members of regulated SMSF's who take advantage of instalment warrant arrangements. Of course, no investment is without its risks. For this reason, YOU MUST ensure you are talking to lawyers and accountants who are really across this topic. I've got names of some lawyers and accountants I would recommend - PM me if you are interested.
Also, please note that many brokers are now offering "SMSF products", with little more than the basic understanding required. I am not a broker, and I don't mean to displace them, however, this is a lucrative industry and many people have jumped on the bandwagon without getting and understanding all the information (or as best as could be hoped in an area still as infant as this one). Be careful. Speak to professionals.