The rotary vane pump on a distillation system that's made to separate the fractions of cannabis extract is the workhorse of any system. But to be honest with regular oil changes it'll last as long as your moms Toyota Corolla in most cases. But unlike your moms Toyota, there are a few pump companies that really dial in the precision with low vacuum distillation of cannabinoids.
I like to use two sets of pumps for a distillation when I know there are other fractions with significantly different boiling points then the main cannabinoid fraction. These I call the soak pump and precision pump. The soak pump comes on first, it has a high cfm and a relatively good ultimate vacuum depth. but it MUST be extremely reliable, if this pump goes down, all hell breaks loose.
If you've experienced some level of cannabinoid distillation, imagine this. You have 14L of BHO THC crude in the boiling flask, it still has some butane in it even. If you get that fraction to 100C with a full stir and have a power outage, or a pump dies, you better be right there ready to slam open a clamp and release the gas boil off and even still you may be in for some troubles. I trust my Sogevac and the Cacejen soak pumps I have. Barring a power outage, I'm not expecting them to go down during a run, but it has happened to me. I received a pump to R&D from a company at one point, advertised as able to handle 45+cfm and capable of vac depths as low as 1 micron, I figured it would make a good overall pump, soak up a first pass and get a decent vac depth during mains on a 20L, and with a good oil change, handle a decent second pass at good depths. Well, during the first pass we had just crested the decarb stage around 130C when the pump died. It just turned off suddenly, no warming, no whining, no signs of heat, just, off... Immediately we pulled the plug on the setup and swapped over to an Edwards 30 I had sitting next to it. This means I opened the system at 130C (pretty much a no no) I grabbed the whole pump in one go and took it off the table and put it behind me, I slid the e2m30 on the stainless table. Reattached the system and turned on the pump and continued. Not many people can do that in general with a spare pump, let alone the quick change needed. Had it been 10-15 minutes earlier this may be an entirely different story. I then called the company. FURIOUS... I gave the pump one more shot and it did it again to me but this time I had the second pump valved into the system to be able to switch over. I then took the pump back and left it on their door step. Had i not been lucky and good at what I do, that could have cost me alot of money or worse, could have harmed me.
With all that being said, I have never had any trouble with my Edwards or Cacejen pumps. Especially with the power section. Plug them in and go. keep them clean and you'll never have to rebuild them. To this day I have never rebuilt my Edwards or Atlas pumps, and have only rebuilt the Cacejen pump after we poured distillate in the oil reservoir to see if it would still run. We only rebuilt it to look for damage, which there was none.
I did a test of a side by side comparison on a Cacejen pump vs an e2m30. based on the advertised specs, they were extremely similar and when I had first heard about Cacejen, I don't believe they were really being used in cannabis. Both Summit Research Tech and Cacejen were curious about the results so they helped fund the R&D process. First we checked ultimate vacuum depth on a brand new pump, I hooked up an Edwards p3 that had routinely tested to be accurate in its full scale. Both acquired the fabled 0.75mtorr as advertised. Then I attached them to a 20L vessel in the same configuration and pumped out the vessel and measured how long it took. I then did this again after both pumps had warmed up for an hour. The Cacejen was about 2 minutes slower on complete pump down. This only means the vane is slightly smaller and were talking hair difference here considering that they both did it to the same depth. From there I ran both pumps on the same system with the same material. I did this test one after another, so it wasn't a direct test but I logged temp and pressure differences, the Cacejen actually did better in this test. Mind you this wasn't a used Edwards 30, this was a brand new atlas 28. a $6,000 pump. I ran a 5L at peak speed and the Cacejen finished first with better vac depth during mains. From there the final test was to drain that oil, put in just enough oil for the pump to run and add 100mL of distillate directly into the inlet of the pump. Then turn it on and see how it does after 4 hours, they both got pretty hot but neither turned off. I then turned off the pumps, allowed them to cool and then restarted them, same results. I then went to use the Atlas the next day on a system and the pump wouldn't turn over, I had to turn it off and on a bunch of times while heating the case with a heat gun until it fired up. I then used the Cacejen on its next run, just fine. Part of the reason for that is the Cacejen has a bigger oil reservoir, so it tends to thin out the contaminate loads better.
After all these tests, Summit actually asked me to throw silicate in the inlet of the pumps, which I declined to do. All in all I still use both pumps with great success. There are few pumps I can say that about. I've brought back a Welch pulley pump from the dead before after someone had crude flow into it, and i've used a small amount of Alcatel pumps, but nothing seems to be as precise as my Edwards or Cacejen. Specifically the Alcatel pumps on Ebay are retired J&J pumps used for vacuuming off hydrogen peroxide from sterilization so alot of times they are contaminated and full of rust. Their vanes are shot from being ran for so long that they tend to never acquire good depths no matter how much you clean them. They're cheap so a few of them can make a good soak pump array but i'd never trust one for mainbody if I was aiming for my best work.
Obvious part of this is opinion based and i haven't tested everything but from what I have seen, this is what I prefer and why. there are alot of pumps out there and companies so don't limit your exposures, but just know, its best to have a solid backup just in case.