I have two of the jyetech pocket DSO scopes, with the latest firmware it now does 20Msa/s.
(before it was about 2msa/s but it now incorperates equiv time sampling.)
Now I agree it is a "toy" but a reasonable starter for learning the basics.
[I'd rather let the kids learn scope basics on the pocket DSO than the rigol.]
It only has a 1Mhz bandwidth and is only really useful for signals up to 500Khz.
The built in frequency counter can be used up to 5Mhz so for the money it's ok,
(and the FFT function on it is .... well it's there but not really useful).
Now I'm not endorsing this as a serious scope, but it's a reasonable beginner scope
for learning triggering etc and is a fun (but frustrating due to poor instructions)
project to build.
This is the real reason why I got some for the construction fun.
Daisy chaining both scopes (trigger out to in) I found them quite useable for basic pic work, until I wanted to measure the clock signal
.
Obviously though if you can get a proper bench scope do it, I got the rigol 1052E and do not regret it at all.
now my experience as a hobbyist, I found a few times when a scope would be handy (prompting the "toy scope" purchase)
and soon hit the limitations of them, prompting the purchase of the Rigol, end of the day most hobbyists do not "Need" to own a scope but it's nice to have one, and once you have a proper one you won't do without it.