I've had 3 orders arrive in the last week (2 on Tuesday I think) and one today - 1 was dispatched 17th Mar, one on 23rd and the last on the 24th. Singapore post has improved, and they seem to be taking around 3 weeks at the moment.
All post systems can be tracked by independent tracking sites - I use
http://www.17track.net
This gives very accurate information of when it's received by the postal service, when it's dispatched to UK (though this actually always seems to be when it goes into the container for the UK, not necessarily when the flight leaves), then you get an update when it arrived at Heathrow, and it usually arrives 2 days after this.
It's definitely worth it in my view - I've bought things I wouldn't dream of spending original or UK prices for, but I have spent the extra couple of quid on some original Kanger and Innokin tanks from UK vendors if the prices haven't been silly (it's a real luxury getting something within a day or two when you're used to waiting weeks).
I had quite a spending spree in March, so parcels are coming in thick & fast at the moment, but I have a Nemmie only just left FT (delayed stocking) and a 134 clone that doesn't even have a shipping date anymore.
I haven't returned anything, though the only really useless item was a mini dripper that had a 510 connector a good millimeter at least smaller than a 510 fitting - I raised a ticket, but they would only address the issue if I sent it back, which just wasn't worth the hassle for the couple of quid it cost me.
The threading on a 510/ego adapter I got today isn't up to much, but again, it's not worth the trouble for the minuscule cost - the savings more than cover the odd low cost dud (I've spent about £500 with them in total)
The Brass mech I got today is just wonderful - can't wait for the copper nemmie