My hardware: OG V1 Switch, fully cleaned of dust. Installed an aftermarket (and allegedly better than stock) fan and battery and with newly applied (high quality) thermal paste.I exclusively play in handheld mode and overclock just enough to make the targeted framerate (either 30fps or 60fps depending on the game) rock solid.With that context in mind, this battery grip offers two big advantages for overclocking:1. Much longer battery life. I am talking I was getting maybe 2.5 hours max before this device (about 80% brightness, speakers on about 70%, with airplane mode on) and now with the device I haven't managed to deplete the battery pack in a single day (talking like 7+ hours of OC'd Xenoblade). I imagine a V2 or OLED will get even more battery time especially with stock clocks.I'll try and do specific max time testing and update the review with those numbers at some point.2. More overclock options. Let me explain. Using "sys-clk" you are limited in the max clocks you can use in handheld mode, unless you are acticely plugged into a charger. This device counts as a "usb charger" which will increase your GPU handheld OC options from:GPUStock 307MHzOC handheld max 460MHz*OC handheld max w/this device 768MHz*So what's the big deal? Many games can hit a mostly solid 30fps/60fps (again depending on the game's target) with the 460MHz OC option that you can get without this device, however many games will still have areas or certain actions (spells, dense mobs, or something) that can tank the FPS for a few seconds or until you leave that area. If you're like me, that will bug you and this is your solution.I find the 537MHz option (which is not possible without being tethered to a charger or by using this device) eliminates almost any and all dips. Even then, you still have the option of 614MHz, 691MHz, and 768MHz (which is docked mode clocks btw) to smooth out any additional dips, should you wish. Prodeus (w/ shadows) being the most intense I've found, needing 537MHz & a high CPU clock 1428MHz just to hit 30fps, and more to reduce dips.I personally don't like to go above 537MHz because I hate fan noise and even 537MHz pushes fan spin to around 35% which is almost loud enough to annoy me personally, at least without headphones on. I also find that if the clocks have to be pushed past 537MHz for handheld targets, the game is probably just poorly optimized and either nothing will make it stable or it is cpu bottlenecked and you need to bump up CPU clocks as well.So what are the drawbacks?1. Heavy. Like I would never lay on my back and hold it above my face heavy because it might break a nose or chip a tooth if I drop it heavy. This is more of a use your thighs to prop it while you play unless you really want carpal tunnel heavy. Switch is 1lb 11.6 oz (or 27.6 oz total) with the grip and 14.8 oz without. It's a pretty big difference at almost double the weight. If I were the company I would offer one with half the capacity and weight for the mainstream market. Obviously I am glad this exists in this form as I value the capacity over the weight but I feel like I am pretty niche in this preference.Side note, I don't really use the stand but it is far better than the V1 Switch stand. Tabletop mode + the usb slots the grip has on top + pro controller might make for a great alternative to counter the weight issue.2. It is big. I imagine it would be problamatic for someone with small hands but for me it is just right. I can play bass and 12 string guitars pretty comfortably for reference.3. It's a little smooth. Same smoothness as the Joycons but in my opinion that is a little too smooth with the added weight. I haven't had any close calls (yet) but I do have to be mindful to not hold it with one hand as the smoothness plus the additional weight (and some sweaty palms) could lead to a pretty catastrophic drop. Still coming up with a home solution for this but it might just be grip tape around the whole outer perimeter where your hands cup the grip.Summary:For me, overall it is far more comfortable than without a grip, which is why I originally purchased this. I don't feel like my hands have to turn into spider legs to hit the triggers anymore or feel like the joycons are flexing ever so slightly. Just feels more solid overall.I truly thought the battery would give me an extra hour or so back (you know, return the battery time lost from overclocking), not give me an extra 6+ with overclocking. Not having to worry about afternoon charging to be able to play it again at night is really nice. The additional overclocking options are a huge (and entirely unforseen) bonus as someone who plays exclusively handheld and hates fps dips.No external heat that I can detect on the grip (at all) but the internal temps seem to run a little higher abt 3 to 5 degrees (which just equates to more fan spin, nothing more), so I will probably remove the intake grills on the grip like the other reviewer suggested and see if that brings it back down.Edit: Removed the fabric mesh and the "tape" mesh from both the intake holes on the grip and the temp dropped back down about 5 degrees on average under the same load. Two layers and both were pretty fine/small openings so I am not surprised airflow was a little restricted.Worth every penny. Hope this review helps out a very specific person or persons. I will try and answer any questions asked about the device.