What are your thoughts on POSB invest saver?

POSB InvestSaver was one of my first investments when I started out years ago.

If you're looking to invest in a REIT ETF using this RSP, you may instead want to consider investing in Syfe's REIT+ portfolio instead. The monthly sales charge for this RSP is 0.82% per transaction, as compared to Syfe's 0.65% p.a. management fee. You can also invest in the ABF Singapore Bond Index Fund through the REIT+ portfolio.

If you're looking to invest in the STI ETF, this RSP is one possible way of doing so. However, do take note of the counter-arguments against the STI ETF. Chris gave a good succinct opinion on it here. One possible argument for investing in the STI ETF is that it gives you exposure to the Singapore market. No right or wrong, it really depends on your investing beliefs and risk appetite.

As for unit trusts, I can't comment much since I didn't use the RSP to invest in them.