It might be hard to justify the expense if you only plan to use it once. But there is no better way to apply spray foam. If you use this product you will never use the straws applicators that come spray foam.Pro tip: make sure you get a can of cleaner to use after each use. If you are using this every day for work then you can leave to spray foam attached to the top as long as you close the control valve via the black knob on the rear of the gun.This is great. Now I can do small stuff without wasting the whole can.This is my first foam gun. I got tired of all the mess that the cans of spray foam typically make. My only complaint is that, even after following all the instructions, and closing the control valve immediately after each use, I can see that the output of the gun is decreasing. I used the spray can of acetone after each bead application to keep the tip 100% clean. I am afraid that it will likely stop putting anything out in a very short time. I used this for about 5 days, and can already see the output declining. The control you have over placement of the foam is amazing and makes a nice clean bead. I just wish they lasted longer.I used this gun with Great Stuff crack filler spray foam. I added board insulation, and sealed gaps and seams with it. Before this, I used the smaller cans of foam with the plastic spray nozzles.The screw knob to control the rate of foam discharge works great. It is also nice to be able to store the can on the gun for a few days between use. If you switch cans immediately, you don’t need to use the cleaner in between. But if the can is off for more than a few seconds, the foam can cure in the gun and ruin it.I bought a can of cleaner also to clean the gun when I didn’t put another can on. The cleaner worked good too.The upfront price is high for myself, but did buy because it could not be worse that using the small cans due to the one time use, even the ones saying the can be use over a period of time. The reason this is worth the money is after using only about a half a large professional can, I left it on the shelf still on the can for seven months. After cleaning the tip of cured foam it acted just as I opened it for the first time. The control of flow is excellent and the long reach is great. If you remove it from a can and not planning to reapply to another right away, you will need to buy the cleaner to spray through the gun.So far, so good, but I have not tested out the open can shelf life yet. That said, it's way more controllable than a can - like way more. If you have a lot of areas to address that would benefit from thinner or at least consistent bead size, you'll save a lot of spray foam using this over conventional cans.Things that could be improved or added:* A hard (or even soft) case would be wonderful. Add it and charge and extra $10-15.* An adapter kit with hoses for hard to reach areas. This gun fits in fewer areas than a can does. (There are DIY hacks for this, however.)* Shorter, fatter can options as well to allow the gun in tighter areas without losing too much can volume.I should have gotten this sooner!Excellent control over the foam bead size vs. the disposable can / straw combos with very little waste.The narrow tips that are provided are optional use and do cause more "post release leakage"My friend has an older model that has a barbed tip vs. the current smooth tip. With the barbed tip you can attach tubing to help direct foam into harder to reach corners, which isn't an option with the current model's nozzle design.On the plus side, the current design is easier to clean.Tip: don't remove the can and use the cleaner after each use. Keep the can attached, wipe the tip with acetone, and use the gun (even if just to dispense a little foam) every 3 weeks or so and it will keep the system sealed and minimize waste.Haven't used it yet , looks like it will work just fine .High quality, performs well. Expensive. Must have for any foam application construction projects since you can use the foam at your own pace without it spoiling (typically with regular cans) and reduces foam waste. Hard to find cans of great stuff pro at the hardware stores (Amazon does not sell it)I used it once or twice and it worked fine later on I try to use it again and for some reason the foam was not coming out! Gave it a deep clean and no changes, so I thought maybe it was the foam so I try a different gun and the foam was not a problem , turn out the gun was not working, it was a good gun and it work but losing it once or twice it's too much for it,If you are doing a few windows, this is the way to go. It's worth the money. You save on spray insulation, easy to use and clean up.So far so good. Works as advertised. So far I have not wasted any foam cans like I have done in the past.I like its durable build. Works better and longer if cleaned after use.