Value RAM - ...say wha'?

Well this is fairly new to me. Looking at the prices they cost at around 60% the price of a same-spec RAM which isn't value. As far as I've been able to farm off google searches there'd be some downsides, of all the inability to overclock one as much as you would a "normal" RAM was the most underlined. Now I've never OC'd RAM in my life so I won't be caring on how good it is at that.

I currently have 1 gig "normal" RAM in my computer and I'm thinking to buy another 1GB value RAM. For the record, both are 533Mhz DDR2, and I do not have dual channel. I'm thinking, hey, it's a Kingston. Even if it's more cheaply made it's still gotta be good right? Aside from the OC-ing issues which I don't care about I would like to know a few things, if possible from one who's had to deal with this type of memory:

-wether to expect compatibility issues with my "normal" RAM stick
-just how much of a performance loss is it? I mean games, system startup etc.
-are they reliable? do they break quickly? vulnerable to memory leaks? ever suffered one?