It depends on many factors. eg: whether they & you have free upload & download slots & bandwidth at that specific moment, net traffic, etc. It's much easier to browse someone who has Chat enabled. Some other gnutella clients are extremely difficult to browse. But be patient. In my experience, one moment I couldn't browse someone, then 10 mins later I could. One minute a browse shows they have 60 files, 15 mins later it shows 600. So browsing is not always reliable.