Comcasts DVRs here in the SE are clumsy. Poor UI. And the monthly is higher than Directv.
From your current description, it reads like the HD is failing. Considering the HR21 was introduced in 2007 (I think) your scan errors and lock up etc indicates a HD in early stages of failure.
If you had an HR24, you'd be very pleased with the speed. H25's are even better but are non-DVRs.
There isn't any CSR that can promise you and HR24! While they can promise but can't deliver. No matter what. Don't let them tell you otherwise. You can order a HR34 but while fast still some s/w nuances since its new. That's an HMC on the order form.
If you want to stick with Directv and want a faster DVR, the HR24 from a retailer is your best bet and if you want 5 tuners and don't mind a s/w glitch or two, then the HR34 from Directv or online/retail are your choices.
From your current description, it reads like the HD is failing. Considering the HR21 was introduced in 2007 (I think) your scan errors and lock up etc indicates a HD in early stages of failure.
If you had an HR24, you'd be very pleased with the speed. H25's are even better but are non-DVRs.
There isn't any CSR that can promise you and HR24! While they can promise but can't deliver. No matter what. Don't let them tell you otherwise. You can order a HR34 but while fast still some s/w nuances since its new. That's an HMC on the order form.
If you want to stick with Directv and want a faster DVR, the HR24 from a retailer is your best bet and if you want 5 tuners and don't mind a s/w glitch or two, then the HR34 from Directv or online/retail are your choices.