Two big differences: cost and dosage. Many Coloradans don’t know about the excise tax paid on all flower grown for rec consumption. 15% is paid when flower is sold by the cultivator, and flower is obviously the source for all marijuana consumed, whether it is smoked bud or converted into vape, concentrate, edibles, etc.
Medical product has no such tax, so it is ALWAYS less expensive.
Dosage is a huge difference. Because many patients need higher dosage to treat their condition, medical dispensaries offer many of the same products in higher dosage. For example, a chocolate bar in a rec store will be limited to 100 mg THC, whereas a medical dispensary will offer the same bar in 250, 500 and 1000 miligrams. Another example: Kief Cola in rec is limited to 10 mg, but the same product in medical contains 100 mg.
Sure, an annual red (medical) card costs about $70, but that cost is often covered in only one or two visits to a medical dispensary due to lower prices and higher dosing.