I've recently picked up biking again since my childhood years, so I'm quite the newbie. I've figured out most of the features I'd need so far but I'm at a loss at this one. Why would you pick front suspension?
In my case, I'll be commuting 5 miles each way every day, 1/2 through paved road and 1/2 through gravel trails with a ~200m stretch of moderately bumpy off-road.
Proviso - my advise presumes you are not looking at forking out $2K or more for a bike, and probably significantly less. At a high price point I might suggest suspension. I also presume the gravel section is well maintained with average (pea - grape) size gravel (Where I ride, we sometime use logging roads, the "gravel" is stones about 2"-3" across.), and straight rather than technical single track
Advantages of suspension - Softens the ride on the arms making the ride more comfortable, holds front wheel on the ground providing better handling, especially while cornering. Allows you to ride a straighter line than you might otherwise be able to.
Disadvantages: Heavy and very expensive for good shocks, need maintenance and cheap ones don't really work well. Absorb energy while riding slowing you down - can be mitigated with a lockout, but even ones with lockouts move a bit.
You only have 200m of rough ground to cover, so a suspension fork is probably overkill. If I was buying a bike for that commute, for the same $$$ you will get a significantly better bike with no shocks, any loss of time over 200m of rough ground would be made up on the rest of the 5 miles because of the better quality bike. Cheap shocks won't really help with the comfort, so unless you can get to at least a mid range in price, don't bother.
I would consider padded hand grips and gloves - cheap and easy to "tweak" if needed. Also big tires will help with the rough ground and gravel - I would look at 1.75"-2" slicks, and probably a 29er MTB of cyclocross style wheels (depending on your height).
Consider a quality steel frame if you cannot afford carbon - they absorb vibrations much better than aluminum. The problem is many shops do not stock, and know nothing about steel and will tell you "stories".
They ride the paris roubaix on road bikes, and that is a lot of cobblestone. You can get away with 2 miles of gravel without suspension. Don't go overkill on this. You can ride gravel on fat tires and no suspension. You don't even need a mountain bike.
Get a touring, cyclocross, or hybrid bike with cantilever, disc, or mini-v brakes and put some 35mm or larger tires and you'll probably feel like you are floating over it (unless you have seriously bad wrists). Run your tires at the lower end of the recommended pressure and they will provide a lot of cushion. Use puncture resistant tires or install tire liners to prevent flats.
If it gets muddy on the gravel, you may want to get some tires that are a bit knobby as opposed to slick. I also recommend a steel frame (or carbon if you want to spend a bit more) to take up some of the bumpiness on the ride since aluminum is much stiffer and will not feel so good on rough terrain.
Suspension works great if you are riding a mountain bike on singletrack trails. It's pretty much overkill for anything less. You probably won't really be digging hard in to corners on your commute. If you get suspension, You're probably going to need a relatively heavy bike compared to a road bike (unless you spend big bucks on all carbon) and you'll likely be slowed down by the bounce introduced by the fork (even with it locked out) and your bike will likely have much lower gear ratios since they are meant to be used off road.
If you are really sold on suspension and plan on riding on the road (and a few gravel trails) primarily, you probably want a hybrid with a short travel front fork.
It mostly depends on your riding style. If you ride neat asphalt all the time there is no reason for it, on the other hand it helps to maintain control off the road, so the front wheel will stay in contact with the ground and helps to save your joints from the vibrations.
IMO in your specific case, it's better to save your wrists and get a short 80mm suspension fork with locking, so you could lock it on asphalt and open on gravel/off-road. Just remember to unlock it off-road, else you'll ruin it.
