OK so I got my Retro USB AVS about 2 weeks ago. I've had time to muck around with it update it and use all the features. There are tons of reviews for this thing, but there is a lot they don't talk about. First of all, YES the thing has a death grip on your carts, The NES Slot will grab your NES games and it takes a lot of effort to remove them. The Famicom Slot isn't as tight as reviews have stated BUT it is very finicky. You have to put the Cart in just the right way or it'll be read wrong. My Famicom version of Kirby's Adventure does not get along with my AVS and sometimes I have to fiddle with the cart and turn the system on and off a few times before the game works correctly. If you plan to get an Everdrive and use it with this, get the NES version. Third, The Firmware on the second wave of consoles is the original they didn't bother to flash it with the newest firmware. The Update is easy to do. There are issues with the firmware, sometimes it doesn't load correctly or is a garbled mess. It randomly resets color palettes (I'm using FCEUX as my default) and that sort of thing. Oh the picture I have NO complaints about. NONE the scanlines are as good as the Framemiester. I think it's a good product but these things are not talked about in reviews and I felt the need to address them.
I have no complaints on the NES slot on mine, it might be tight but nothing anywhere close to the vicegrip lock of the Retron 5. I actually had that one rip a PCB from the shell on one cart. With the AVS, I can actually remove it with my fingers rather than having to grab the cart with one hand and hold the system down with the other. The Famicom slot is a disappointment. I'm a fan of unlicensed trash, most of which use weird mappers that require original carts to work. Using a pin adapter in my NES is a pain due to constantly reinserting the whole setup to work properly, and not too much easier on a top loading clone that I just leave the adapter stuck in. The Famicom slot on this is picky beyond belief, to the point I'd rather deal with either of the above mentioned options than spend 10 minutes reinserting a cart that I know has perfectly clean pins. Many people bitch about the cart flap but I don't see the issue. It's only a problem when playing Famicom games, and I'd much rather have a flat loading NES setup than the alternative of a NES cart sticking up like a wedding dick.
Cart flap doesn't bother me. I know now I'm not getting the Famicom Everdrive N8 or if I do I'm getting an adapter defeating the purpose of the cheaper Famicom N8. I hear the Analog NT isn't much better either.