I often wonder why nobody bothers to design under-sampling scopes. I have an HP54610B with 700MHz frontend followed by a 20MHz 8-bit sampler, 700MHz isn't a typo it was calculated from the rise time. Sitting behind me, a TEK 7854 400MHz BW with 200kHz 10-bit sampler, actually it might be 400kHz sampler, anyway it's a bit random and drifts a lot. It really is a random sampler !!
For repepitive time domain signals they're both good scopes but only 8-bit or 10-bit accurate at best, no good for RF. I use a spectrum analyzer for RF not an 8-bit or 10-bit scope. For RF, down sample to base band and use a 16-bit ADC, simples.