I have i-Cable 130mb (on paper). 130mb is relatively commonly advertised speed with DOCISS 3.0 cable modems. In the US I think I was advertised 110mb with the same Motorola-brand modems. I-Cable is now using the Motorola modems that are being rolled out in many parts of the US (Comcast) with DOCSIS 3 which makes it helpful in troubleshooting as there are many folks talking about them on the net.
Now, do you really get that? Do you really get whatever is advertised by any of these guys? I think the fine print of all the ISPs here say "only to Hong Kong websites". Using the popular (but not totally accurate site) speedtest.net I can regularly get 60mbps from the servers in Hong Kong during the day (right now it is 30mbps but I think the kids are donwloading something in the other room). Going over the oceans to say the US or UK it drops to 4 or 5 mbps, though usually quite less. Quite a difference.
At some point everyone's connection is shared. It could be the number of users in your building sharing a cable connection back to iCable, or it could be the number of DSL users in the phone company's central office sharing the same connection out to the net, or it could be all the users of a particular ISP sharing the limited overseas bandwidth available. Your speed is going to be constrained by the weakest link. In some houses with very old routers, you can even start to run into problems with WAN-LAN throughput ports in your router which maybe less than the current offerings from PCCW or ICable (my old firewall had a 7mb limit). Here is a good breakdown of WAN-LAN of many popular routers.
Router Performance Comparison Charts - WAN to LAN Throughput - SmallNetBuilder
So, in the end, is it worth it? I have the 130mb package. I get maybe get half of that to Hong Kong servers and even less to the US. Still, I'm able to stream video from the US or UK (even when using a VPN) and websites load "fast enough" for me. I occasionally notice some speed slowdown when I'm working with some databases in the US that load large queries before displaying them at my end. My wife uses a CITRIX connection to her servers here in HK so having the added bandwidth for HK only helps there. If it was just me poking around websites overseas, it is probably a bit of overkill.
You might want to ask folks in your building what they are using and whether they are having any problems or success. Is HKBB or HGC an option where you live?
edit: One more anecdotal bit. I've had relatively good service from iCable over the last year. The original install took 6 hours from the time I ordered service until the time it was installed. I had one outage after 6 months which turned out to be a frayed cable that was pulled out of the wall by an overzealous cleaning lady. My second outage, which required customer service last week, lasted about 6 hours (time I called until the time they could get a techie to my house). There was some noise in the line and he had to go out into the stairwell and work on something out there. Got a nice screen shot of the web-based control panel he was using to look at the 'node' or whatever it was called out in the hall. I've had other minor outages that never lasted more than a few moments--not even worth calling the support number.
Of course, your mileage may vary when it comes to customer service. Some have horror stories.