L3302 is a 'tractor tractor.' The LX is 'mower tractor.' L has cast iron rear end and heavy duty everything for abuse (digging and going through brush). With a loader, backhoe, and filled tires, it's near 5k LB.
The LX3310 goal is to be lighter weight so that it can mow better. The rear end is lighter duty aluminum. Axles are smaller. Loader is lighter. The tractor is similar size, but is a bit smaller.
There are more features on the LX3310, but the L3302 was recently updated to add some of them. The LX mid PTO lets you use a front snow blower so maybe that is something to consider if you need that or also maybe you don't so it's a waste. IMO, if I was dealing with snow, I'd want a front snow blower. My john deere x590 can get one if I wanted, but I don't need it...maybe your mower can get one too.
L series is kubota's largest seller and the best selling tractor in the world by a good margin. There is a reason for that... Having owned a L3301, I can see why and would recommend. The only downside that stands out is the HST is whiney (though they all are to some degree...only the grand L series advanced HST is more quiet), but stuff like no tilt steering wheel etc wasn't a concern. I liked the simplicity of it.
Owning the L3301 kind of always had me wanting 'just a little bit more.' It can handle doing like 90% of tasks you want to do with a tractor, but for some stuff, you need bigger to do it faster and safer. If you're thinking of for example moving 12-16 foot 20+ inch diameter logs, you should go bigger. An L3301 will lift, move, and load a large IBC tote filled with wet firewood, but it's kind of sketchy on slopped ground. It wont move a filled IBC tote with liquid or even near 1 pallet of concrete or brick. It has decent ground clearance, but still not quite enough to go in messy dirt/mud, or woods (lacking protection). It is mostly designed to be a 'smaller tractor' to handle daily farm tasks where using the huge ag tractor (probably hooked to some large implement) would be inconvenient.
For my usage, if I were to do it over again and wanted an ag tractor, I'd jump straight into an MX sized machine (similar power/ size as my L47). It does cost more, but you're getting more for your money. Coming from a B, if you go sit in one today, you'll probably think it's too big. Try again after you used an L for a few months and you'll have a different opinion.
I agree with someone saying going with + 2x the weight if you're looking for a decent upgrade.