TL;DR: The RTX 3070 Razer Blade 15 2021 Advanced Model is pricey, but you get what you pay for in both performance and package. If you can afford it and you need a high-powered mobile computer, this is well worth the splurge. This review covers both my general opinions of the laptop, and a few notes on its improvements over last year's RTX 2070 Super-equipped Blade 15 2020 Advanced Model.
An acknowledgement to start: this is indeed a very expensive laptop. Could you get comparable performance in a self-built desktop for much less? Most definitely (provided that you can find an RTX 30-series card for anywhere close to MSRP - I'm looking at you, eBay scalpers). In my opinion, though, you're paying for the portability, not just the performance, when buying a gaming laptop.
Out of the box the reason for this high price tag is quickly evident; all those expensive, high-performance components touted by Razer are enclosed in a sleek single-block, precision-milled aluminum chassis, cool to the touch and providing a premium feel definitely not matched by the plastic often found on lower-grade Windows laptops (it compares favorably to family and friends' MacBooks, I've found). The one downside to the black anodized-aluminum finish in previous years has been its status as an absolute fingerprint and smudge magnet; I found myself using the included microfiber cloth to wipe down my laptop after almost every use with last year's model. Razer quietly advertised this year's finish as improving this flaw, and to my pleasant surprise they've followed through - fingerprints appear much less frequently with this new, visually-identical finish. The touch pad is large and satisfyingly responsive, though I prefer using a mouse. The keyboard is nice and clicky; I've heard complaints about the travel depth of the Blade's keyboard but I personally find it a welcome change to the last Dell I used. The beautiful RGB Chroma for the per-key lighting, enabled in the onboard Razer Synapse 3 software, looks gorgeous, and offers more customization options than I'll ever be able to figure out. The slim size of the laptop is lovely; my old laptops, despite having the same screen real estate, look like veritable bricks compared to the Blade, with its slim bezels and small footprint.
You're spoiled for choice with ports: three zippy USB 3.2 Gen-2 Type-A ports with great transfer speeds, one latest-gen UHS-III SD card reader, an HDMI 2.1 port, two USB-C 3.2 Gen-2 ports (both now Thunderbolt 4-capable) able to power the laptop, a DisplayPort (via USB-C) and a 3.5mm audio jack. (For those comparing to previous models, the changes from last year port-wise were HDMI 2.0b to 2.1, and both UCB-C ports becoming Thunderbolt-capable, conforming to the Thunderbolt 4 standard and not Thunderbolt 3 like previously.) Even the charging cord speaks to the quality of the product, with a thick, wear-and-tear-resistant woven braid cord providing the power this machine needs (side note: battery life is highly dependent on your settings; to maximize it requires a lot of customization). The speakers are good for a laptop, now incorporating THX Spatial Audio for simulated surround sound. They get louder than I'll ever set them to, and the audio is clear, with decently punchy bass and distinct mid and high ranges. If you're gaming, though, you'll probably prefer a pair of headphones when the fans kick in (they're not airplane-takeoff level like some gaming laptops, but certainly audible). I love the 360Hz screen; its blistering refresh rate makes games buttery-smooth and leaves absolutely no screen tearing. I personally prefer this 1080p, high-refresh screen to the lower-refresh, 4K OLED models for gaming, but for the creators out there those options are available (consider, too, the middle ground 240Hz QHD screen options, sadly out of stock at the time I write this). Color accuracy is quite pleasant, with the screen covering 100% of the SRGB standard. The onboard video camera is better than last year's, thankfully. 720p was sad in 2020, but was also rather-disappointingly par for the course with most Windows laptops on the market. This year Razer finally made the jump to 1080p - here's hoping other laptop manufacturers follow suit. The infrared camera works brilliantly for Windows Hello; between the facial recognition and speedy M.2 SSD boot drive, I'm still surprised by how fast I'm logged in. If you'll be doing serious teleconferencing, I recommend a headset with a mic or a dedicated mic over the built-in set, but if you're only talking with friends on Zoom, the newly-improved stock 4-mic array should suffice.
The performance of the laptop once you dive in is quite satisfying. The Intel 11th-Gen i7 processor is great. While Intel's 11th-Gen desktop processors delivered a lackluster performance increase, their mobile chips gained a marked improvement in single core scores when tested, a larger generational improvement than the last several years. The NVIDIA RTX 3070 graphics card provides just about all the frames I could want. Games run great at high graphics settings; at ultra settings with ray tracing on, Shadow of the Tomb Raider averaged 118 FPS over more than four hours of continuous gameplay last night. This mobile RTX 3070 delivers all the much-hyped performance increases between the 20 and 30-series cards as seen in the desktop variants. The 16GB of dual-channel DDR4 3200MHz RAM is more than enough for my needs, and for memory-heavy games you can download Razer's Cortex software, which optimizes your RAM and diverts it to the game you're playing at the moment by pausing unnecessary background processes. Connectivity is delivered through a new Intel Wi-Fi 6E chip, capable of much higher speeds than AT&T seems to feel like giving me through my modem. Booting on the SSD is incredibly fast, with programs opening quite responsively, and this tier of Advanced model now comes with 1TB out of the box. I added in the 1TB I'd bought to replace the stock 512GB SSD in last year's model, and am now happily sitting on 2TB of storage (Razer makes it easy to upgrade both RAM and storage if you so desire; you can look up tutorials on YouTube).
I couldn't ask for much better performance than the Blade provides; you can look up professional reviewers for better benchmarks on speed and other performance factors (I'm just a college student here happy with a product).