2¢
A suction-side cleaner requires a dedicated port connected to your pump, that sucks water out of the pool.
A pressure-side cleaner requires a dedicated port connected to your pump, that blows water into the pool.
It's possible to convert one to the other, by rerouting a few pipes at the equipment pad, so technically you can't really make a mistake choosing one or the other at this point.
Even if I knew I was going to have a robot (which doesn't need either type of port), I would still run a dedicated vac line from pool to pad, I just wouldn't connect it. Pools last a long time. Technology changes. Maybe the "next new thing" will need a dedicated line. Maybe you'd like to run a manual vac once in a while, for a quick cleanup. Maybe you'd like to sometimes run a fountain or similar water feature in your pool. Maybe one of your return lines will fail and need to be sealed up (that's a thing). You can't replace something like that, so the extra line could be used as a spare. This notion is unconventional, but that doesn't mean it's a bad idea. Worst case: you cap it off at the pad and plug it up at the pool and forget about it until you might someday need it. It's cheap future-proofing insurance.
OK, I've had both pressure- and suction-side cleaners. I can't recommend a PSC, for a lot of reasons I'll elaborate on if you ask. For a pool that will stay relatively clean, a SSC will serve you well. Some will argue that they require more electricity than a robot, and technically that's true, because a SSC makes use of your main filter pump. But your running your filter pump everyday anyway, for filtering and circulation. Well, while the SSC is running, cleaning your floor, it will also be filtering and circulating your water, so I consider the vac run as part of the filter run and so practically speaking they don't use significantly more electricity.
A SSC cleaner sends its gunk to your main filter. Larger items are trapped in the pump basket. I have a relatively clean outdoor pool and only clean my main filter once a year. A robot collects its gunk onboard, which means you have to haul the robot out periodically and clean its collection bag (or tray). I have to periodically clean out my pump basket, but that is a lot easier than hauling a robot out of the water. How often (for either cleaner) depends on how dirty your pool gets, and with what. In your case, you might never have to clean the pump basket, as your gunk will be smaller and pass through to the main filter. I could theoretically ignore my vacuum indefinitely. It can live in the pool and requires nothing. The same cannot be said for a robot (because of its collector). And while some leave their robots in the water all the time, I believe that contradicts the owner manual (at least for some brands/models). The robot requires electricity, which means while it's in the pool, you'll have to look at an electrical cord draped across your deck. Not so for a SSC, though it is no less ugly in the water (because of its hose). The combined cons for the robot (the cord, the weight and the cleaning of the collector) are deal breakers for me, and why I'm not interested in owning one. Those items are never mentioned by robot owners, so they must be fine with them (or don't like to admit them?).
A robot will likely clean your pool better. It brushes while vacuuming, something a SSC doesn't do. I consider that a big deal, and the only thing that could change my mind about a robot. But my real world experience is that my SSC cleans my pool just fine. Maybe for some pools that wouldn't be true, depending on what is falling into them. And a robot will brush all the way up the pool wall, including the edge tile. An SSC will vacuum the walls, but cannot come out of the water to vacuum the tile. I don't find issue with that, others do.
I like to remove the vac for guests. A SSC is waaaaay lighter and easier to handle than a robot. I've heard they're pretty heavy. I would not like to haul one out regularly. That will be more true as I get older.
The cost is a non-issue for me. As pointed out there are robots that cost only slightly more than SSCs, but robots with more advanced features can go for $2K (I think). I would not trade my $600 SSC for a $2K robot. A robot has way more complicated parts and electronics, and I would guess servicing a bot would be more expensive than servicing an SSC (which I think some of which can be done DIY). I don't have direct experience with either of those notions, just an intuition about it.
That's my take on the vac vs 'bot debate. I think I included all the major pros and cons. I think my preferred choice of cleaner puts me well into the minority on this topic, as those with robots love them and recommend them highly.
Join me, won't you, in this fight against these invading robots and their mind-controlling overlords! We are a ragtag group, but we can win this battle because we are on the side of humanity!
