I am not sure what manufacturers were thinking when they started using neoprene for diving! Where it has amazing thermal properties it is also really buoyant (thus needing more lead round our waist) and the earlier material used to compress dramatically at depth (thus not only making you really negatively buoyant but also colder because the material was thinner) What neoprene actually is is high density rubber with billions of tiny bubbles spread through it. 

Myth!!

Some people seem to think (because they have been told this by people) that a crushed or hyper-compressed neoprene suit has the same thermal properties as 6mm neoprene suit. Well..... they are actually right ONLY if you are at 30m or deeper! At this depth the neoprene has been completely crushed due to increased pressure on the air bubbles in the rubber. If it is crushed from 6mm to 2mm. Then its thermal properties are 2mm only!   

Thankfully neoprene is getting better and companies are bringing out "compression resistant" materials! But what does that mean??? Basically neoprene suits rely on the thickness of material for your warmth - in essence the thicker the material the more thermal properties you have thus not losing heat to the water on a dive. BUT with that comes more positive buoyancy ( meaning more lead!) "Compression resistant" means that they dont compress "as much" as normal conventional neoprene but they still DO compress!!!

Advantages of these type of suits are that they are more body conforming which gives a better fit feel to the suit. Neoprene stretches so you have flexibility in movement. Average lead needed with an aluminum cylinder in a 6mm neoprene suit will be between 11-16kg.

There is less "suit squeeze" that any other suit making it a little more comfortable in the water. out of the water they arent the most comfortable to be in for long periods of time.

Another thing is that with fabtic coated neoprene suits (even with the hypercompressed suits)  if you get a little water in the suit (maybe through your wrist or neck seals) the fabtic coated neoprene stays damp for a while. You will need to put the suit inside out to properly dry it, .

Maintenance

Neoprene needs more looking after also. You cant leave it in your bag for any length of time. Where the suit is creased will collapse the neoprene and cause a weak area. ALL neoperene suits need to be hung up when not in use. Also neoprene will eventually break down so the life expectancy is shorter than a membrane suit.

Repairing your neoprene suit you will have to patch and glue or use aquaseal liquid neoprene paste to fix holes in your suit. Normally take 24 hours to fix because of drying times of your suit before and after repair

Applications

If you are wanting to dive to 30m or deeper then you must realize that your thermal properties and buoyancy will change at depth. If you want a more body conforming fit then these suits will fit your needs.

What manufacturing companies have now done is said "right we understand and realize that neoprene material isnt the best thing for diving!! SO what we will do is take out all the bubbles in the neoprene so it is just the neoprene rubber and cover it with abrasion resistant fabric! Now we are starting to get somewhere with technology to help us keep warm AND flexible.!!

CN suits bring to the table more body conforming fit WITH a varying degree of insulation in the material. Depending on the water temperature you might not need to wear any other insulation under your suit! This is bliss! BUT if you dive in colder waters then you can choose to add more suitable undergarments to match your thermal needs. Bearing in mind that that you are doing here is adding more body insulation. This insulation is specialised materials and you just cant wear more clothes to keep warm. more on that later.

CN suits tent to also be more flexible too and more harder wearing. There is also more movement in the suit soooooo After christmas you wont find it hard to get into your suit!! (Contrary to popular beliefs neoprene DOES NOT shrink after festivities!!)

The suit DOES NOT compress at all at depth. The suit will still be a little positively buoyant but you will need less lead than a neoprene suit. Price wise it is in the top rang for the front mounted suits but again well worth the investment if you plan on making diving a major sport. If you are a professional then this or the tech trilam suit will suit all your needs and more!

Maintenance

Still need to look after your suit and you cant leave it in your bag for long periods of time. Compression will be reduced but will still crease. You will find that with your natural body bending areas (like behind your knees) the suit will conform to the natural creases round your body So get a drysuit hanger and hang the suit upside down by the boots when not in use. 

Repairing your CN suit you will have to patch and glue or use aquaseal liquid neoprene paste to fix holes in your suit. Normally take 24 hours to fix because of drying times of your suit before and after repair

Applications

VERY popular with technical and deep divers, wreck divers too as the material is really ward wearing. Commercial divers too who are really hard on their suits. 

 Membranes are essentially "dry bags" which have little thermal properties in the material itself so what you wear underneath your trilam is VERY important. These suits take the "bulk" out of diving dry!!

Trilams are extremely light yet very tough suits, in general you will need far less lead than neoprene suits ( on average diving on an aliminuim tank you will expect to use between 6-9kg)

There is more "suit squeeze" than neoprene suits but you are relieving this by putting air into the suit ( this is how you keep warm also) The suits are extremely comfortable out of the water so if you have to spend long periods of time in open wet boats you will love these suits.

In general these suits will last the longest

Maintenance

Your membrane suit cant become damaged if it lives in a bag folded up for long periods of time. the material (normally Butyl trilaminate) is a thin, tough material. Still good to get a drysuit hanger and hang the suit upside down by the boots when not in use. 

If you hole the suit you just treat it like a bicycle puncture, just patch the inside and you are good to go within hours of damaging the suit. inside the suit is a smooth layer which dries rapidly if you get a little trickle into your suit from your seals.

Applications

VERY popular with technical and deep divers, wreck divers too as the material is really hard wearing. Commercial divers too who are really hard on their suits.