There's a bunch of different styles(sprung seat, lever post, air or spring chamber, rubber block) so the experience can vary widely. I've used a lot of them and can tell you that at best, the improvement is very minor, as in they only take the bite out of the most violent hits and not much else. At worst, they act as a pogo stick and at a certain pedaling cadence, you will feel like you are bouncing while riding.

If you're not expecting much from them, I don't think it's a bad thing to try but if you're experiencing pain that's keeping you from riding as much as you want, you're likely not going to get the relief you're hoping for.

I tried a seat post suspension once but didn't like it. It changes your distance to the crank slightly during up/down movement and felt awkward to me.

But then again I don't enjoy front or rear suspension for road bikes for the same reason: that the steering geometry changes with the compression of suspension and alters your turning while in the turn.

The telescoping ones I've tried have all been sticky like a cheap fork. Four-bar linkages like the Thudbuster work better IMO. Though I have never found a suspension seatpost I really liked. It bugs me to have the distance between the saddle and cranks vary without my input.

Can your frame fit bigger tires? I would recommend going that route if possible.

If you want to actually improve the comfort of your ride then I advise you to look at changing your tyres before adding novelty items like suspension seat posts. It will change the riding characteristics a lot more on the bike.

I have a Kinekt dual-spring suspension seatpost that I have been riding on for years. For the most part, I really like it and it works well to smooth out bumps in my ride. It has a decent amount of travel for shock absorption.

However, it requires having the correct springs installed for the rider's weight. If the springs are too soft, you'll bottom out or bounce up and down as you pedal. Springs that are too stiff will nullify any benefit of having a suspension.

It takes time to dial it in, but for anyone who suffers from back or pelvic pain, I recommend a good suspension seatpost.

I haven't tried them. I have heard good things. However, I don't know you and don't know what you know, so let me provide some generic advice for saddle pain that is less expensive and more effective:

1. Bike fit. Either learn to fit your bike to your body, or you can pay a shop to do it for you. Notably, a more upright position will cause more weight on your bum and less on your hands, and vice versa. Also you can measure the width of your "sit bones" by sitting on a piece of cardboard or something, and get an appropriately-sized saddle.

2. Padded shorts. These will make the biggest difference.

3. "Chamois butter'. Basically like a chalky substance that absorbs moisture and prevents chafing.

4. Ride more. Your sit bones will "wear in" like any other part of your body. The more you ride, the more comfortable it will be.

I have a suntour linkage spring suspension post on my ebike. I find it essential for going faster than 20km/h.

The biggest factor for an ebike is your motor assist level. Basically, the less force you apply to the pedals, the less bob you get, and more of your body weight is on supported by the saddle.

Having said that, a suspension post will change your bike geometry. A linkage post will slack back a bit when you sit on the saddle, which would be a problem if you already have your saddle slammed all the way to the front.

Anyway, I do agree that you should start with changing to bigger tyres

My friend swears by their Cane Creek Thudbuster. I borrowed it for a month and TBH, didn't notice any difference on my light gravel/commuter bike. So experience may vary rider to rider