My preference is a sweep second hand. Not sure if I have a Mitchell aircraft clock or not, but it sure looks like one of their very basic analog clocks.
Problem with the digital is that there are more "digits" to remember. With the sweep hand you just mentally picture the clock and you know where 1 minute is for your Holds, etc. For an actual approach, I used a kitchen timer clipped to my Lapboard during training. Now days I have a timer in ForeFlight.
Another advantage of a clock with hands is for fuel balance. I look at the minute hand and if it pointing to the right side of the clock, I should be on the right tank, left should be left tank. So if I was talking to ATC or just contemplating my navel, if I'm unsure if I switched tanks, I just look at the clock.
And then there's your Engine Monitor... the cheaper the clock the less reason not to add the EDM900. Talk to the mechanic and let them know you want to add an EDM and as they are looking at the plane, keep that in mind for work that can be deferred. There may be some things that can wait a year that will let you get the EDM. There also may not be and may be some other big ticket items, but if the shop knows the big picture going into the Annual it can only help.