Awesome info. Thanks a bunch for being in depth with them. Still not exactly sure what will suit me best though.
It depends on a lot of factors, but the two biggest ones by far are the computer you're using to capture (desktop or laptop, Windows or other, etc.) and the different types of sources that you want to capture (what consoles, what types of inputs, etc). And if you already have a dedicated upscaler for your retro consoles, that could open up your options to some otherwise decent cards that don't have 240p support but are considerably less expensive than those that do.
List what you're using and I could try to offer some specific input. Otherwise here are some factors to think over.
Interface (PCI-e, USB2, USB3, expresscard, etc.) - If you're on a desktop, it's usually a good idea to go with an internal card. This might not matter as much if your setup isn't as complicated as mine, but from personal experience, I can tell you that trying to use a USB capture card in conjunction with multiple USB webcams can be a pain. A typical USB bus often doesn't have the bandwidth to support multiple uncompressed hi-def video connections at once, and something has to give somewhere. If you're on a laptop or just have to go USB, go USB3 when possible (i.e. you have the required hardware and none of the features of any USB2 cards are essential for you), but even if you have USB3 ports, you may not be able to find a compatible USB3 capture device if you have the wrong type of USB3 host controller.
1080p 60fps - Until this past year, capturing at this resolution and framerate was strictly in the domain of studio grade equipment in the $1000+ price range. That isn't the case anymore, as both Micomsoft and Avermedia now have at least some products in the $150-$350 range that can do this.
240p/15khz - To my knowledge, only Micomsoft and Startech have capture devices on the market that can support these kinds of sources properly and in a format you'd want to bother to use (i.e. RGB). One of the Elgato devices can as well, but only through composite and s-video as far as I'm aware. Everything else that I have some experience with won't accept anything below 480i/31khz (anything older than a Dreamcast). This may not be vital if you already have a good upscaler, though, as it could be feasible to just use the upscaler to bridge the gap between your source and a different capture card. From personal experience, though, I can say that using the XRGB-3's B1 (linedoubler) mode in conjunction with an XCAPTURE-1 isn't ideal for this; it can produce some weird tearing effects that aren't present when the XCAPTURE-1 is used directly with the source. I'm not sure how reliable a Framemeister would be for this and I can't remember if I ever tried the XRGB-3's B0 mode, and upscalers could also produce different results on different capture cards.
Forced H.264 encoding and DirectShow incompatibility - Anything that connects via USB2 will give you issues here, and these are the reasons why I avoid them. USB2 doesn't have the bandwidth to do uncompressed HD video, so these devices will compress the video with H.264 before even sending it to your computer, reducing the quality somewhat. That compression process can also add a lot of lag to your capture window, which can be annoying if you're livestreaming an event and the people watching at home see/hear the players and live crowd reacting to something that hasn't happened on the video feed yet. These devices also, to my knowledge, never properly support DirectShow, which means that any software that wants to interface with them must be written specifically to support that device. The creator of Open Broadcaster Software
hates that the most frequently-advertised capture devices are USB2, because every last one of them requires him to do specific extra work to get them to work in his program, whereas anything that does uncompressed video and implements the DirectShow API will pretty much work out of the box for the most part, and you'll have an easier time getting those devices to work with lots of different recording software.
Chroma subsampling - Virtually every capture card on the market will sample their footage in less-than-RGB quality, even if said footage is "uncompressed." YUV 4:2:2, 4:2:0, 4:0:0, etc., and not even every 4:2:2 implementation is created equal (see
here and
here). If you can adjust your source device to output to a different color space, like how the Xbox 360 has support for Limited RGB, Full RGB, YCbCr709, and YCbCr601, then you can compensate for this, but otherwise, it means that different capture cards will have varying levels of color accuracy for your input sources. That's why those new Startech drivers are kind of exciting; full RGB capture would eliminate this concern, and I haven't seen
anything else in the sub-$1000 range that does it.
Passthrough and transcoding - Some devices have input and output connections so that you can hook in the source to the card, then hook the card into both your PC and your TV/monitor, allowing you to still play off the TV without investing in any additional equipment. Personally, I don't think these features are ever a make or break deal, as buying dedicated splitters isn't that much of a hassle if needed, but it can be convenient.
DVR functionality - This is pretty much the one and only selling point I think USB2 devices tend to have. Some let you record straight to an SD card without having to hook up your PC. Some allow for instant replay capabilities as you're streaming. Depending on the kind of operation you want to run, that kind of stuff can be useful.
Resolution changes - If you're hooking up old consoles directly to the capture card, the way that it handles 240p/480i transitions can be a concern. Many capture cards won't scale the image at all and must be configured to match the source at all times, making games that switch resolutions a pain. This can also be a concern on PS3, which has a lousy, busted scaler.