PerfectClean Sonic (HX7514/03)

costco warehouse model is about the lowest price you can get for the better motor there are two versions of the motor

My costco sonicare barely works a year in. I wouldn't buy it again

I have a Phillips SoniCare (from costco), but the battery is dying out. Turns out Phillips Quality control varies by their providers, and some end up lasting just after warranty (For reference, I've been having mine for close to 10 years). Out of fear i might be one of the unlucky 15%, I'm gonna give Suri a shot since i like their case has the UV disinfecting feature. I think i'm still gonna try repair my old SoniCare in an iFix shop.

I don't know if there's any good ones.  I guess there was a redesign in 2023? Which may explain why some people love it and others hate it depending on how recently they bought. The new ones seem to have a screw in the body that vibrates loose and makes the brushing action terrible.  The cheap ones/double packs you get at Costco and Sam's club were terrible out of the box for me. The mid-level ones like 3000-4000 series used to be a good sweet spot, but also  vibrated themselves apart for me. The expensive ones also seem to break, and now you're just out even more money.  I had to swap to Oral B despite using Sonicare for decades previously 

Search the sub. Get the sonicare 2-pack from Costco. It’s like $100. 

Costco has sonicare 2 packs on sale for $69. Worth it!

Agreeing with you, we've bought 2 of the Costco Sonicare packs and will be switching (likely to OralB) because these brushes, without fail, will loosen and vibrate as loud as a magic wand when they fail. Not a BIFL product IMO. Great product when they work, frequency and pressure sensing are awesome out of the box.