I use and am happy with the Recon by Rad Elec.

Jessica - Compare the Counts per pCi/L for each unit. Because real estate testing revolves around 4 pCi/l the higher count units have much less variation hour to hour. CRM's only have to be within 25% of the average so all of the certified units can do that but when you compare hour by hour is when you see the large difference in variation. You can easily see the difference between the sun-nuclear base model versus their higher sensitivity model.

I really like the Bluetooth and programmable start/stop times, and compact size, of my Corentium Pros, but my femto-TECH 510s do provide a much smoother "data curve" which is helpful with diagnostics. I haven't really looked into it yet, but I think the RadonEye PRO has very high counts for a less expensive CRM.

REALLY great information here. I'm going to check into all of these options and may have follow up questions but in the meantime, thank you all for taking the time to respond.

I agree with Henri about the Femto-Tech 510. Its been a reliable workhorse for us for over a decade. I have pretty much "retired" my Sun Nuclear 1027 due to its need for AC and its "low counts". Most home inspectors use them here but ONLY because they "cost less". I doubt any of them know what "counts" are! And most terminate them just after 48 hours (because that's the "absolute minimum: the EPA says you must do for a "valid test". But what they don't communicate well is that you have to allow 12 hours for "closed house conditions". I don't think many home inspectors here know what that is. We always let ours run for 72 hours. And Henri, you are right about the high counts on the RadonEye pro. Femto Tech is suppose to release some new units soon. But I sure hope they are Bluetooth compatible and price competitive or I may have to jump ship!

I love the radon eye pro series great pricing and data delivery.

Jessica, I have been using the FemtoTechs since 1991. I have about 40 and have been very happy with their performance--they have a higher cpm. They are currently selling off their used rental units at a very low price to make way for their newer blue tooth enabled units that will be available when the chip shortage resolves.