jimi, I have a Tascam similar to yours, the Tascam 244, and love it!
Although I also have other digital multitracks at home, it has a very nice warm sonic character. From an objective standpoint, the digitally based units have basically no hiss or wow and flutter.
They also have a more extended high frequency response range.
The dbx noise reduction in your unit, however, is very effective
at mitigating tape hiss.
On the other hand, every other format has their problems too.
Computers crash, their fans make noise, and the digital "studio in a box" isn't exempt from ever needing to go in for repair someday.
My 244 is from the early 80's and it could keep working for another 20 years.
Your 424 is quite capable of making fine demo level recordings.
You may want to get the rest of the signal chain lined up first,
and improve your recording skills, then consider if you still want to
keep it or not after you hear how well it can sound.
Make sure to clean it right after your recording sessions to take
any gunk off the recording heads per the owner's manual.
So...
What are you presently using as far as microphones, pre's, etc.?
Chris