It's a good time because all ICOs now accept ETH and ETH price is low now. Investing in ICO using ETH give use a chance to grow up your crypto funds. But you must choice the right ICO. Nowadays there are too much ICOs and not all of them are legit. Scam, fake and no quality ICOs is more than good ICOs.

Generally, the advice would be no, it is not a good time to invest.
There are two main reasons:

#1) the value of btc and ether is really low.  That means that you won't be getting your ico coin for that much of a bargain even if it is priced low with bonuses.
ICO startups are notoriously bad at rolling with the market and making changes.
If an ICO delays their project to a time when market conditions are more favorable for all, that is actually a good sign.

#2) there is very little trading volume out there now.  This means that there won't be much demand for the coin once its listed.  Demand and speculation is what drives newly listed coins up.  Nowadays, almost every ico that newly lists there coins sees the price crash below ico price and stay there.

So yeah, it will be a tough battle.
However, there is the possibility of making profit if the ICO you choose has an enormous amount of hype surrounding it, their hardcap is low, and they have a stream lined ICO time table (like they will only conduct it in three to four weeks and list immediately after that).

I would say these things are more important now than ever before.